Probably about two weeks or so. Hard part is waiting for the ferry schedule. They told me "sometime between October and March." The whole itinerary revolves around that schedule. :-(
With only two weeks you should consider limiting your itinerary to the southern portion of the ferry system from Seattle to Juneau or maybe just the segment between Whittier and Valdez so you can get all the good land tour stuff in your trip.
I put this together a while back for some friends and maybe it will be helpful for you. Most of it can be done via train with the exception of the Matanuska Glacier hike. This assumes 14 - 18 nights and was written with a driving tour in mind.
Fly into Anchorage, most flights arrive late so pick up rental car and overnight in Anchorage. Spend 1 - 3 nights here depending on how much of the items below you want to do. Do not souvenir shop in Anchorage.
Reserve your car tonight. Even if you have to change there is no charge but car rental rates are high and go higher after xmas.
Buy one of these two coupon books for lots of savings. Each hotel or operator only allows so many coupons per day/week/month so book the excursion you want and let them know you have the coupon. 2 for 1 on lots of great stuff.
http://www.toursaver.com/http://www.alaska-discounts.com/Very well done Native History Museum in Anchorage
http://www.alaskanative.net/If budget allows and timing is right, take flightseeing trip out of Anchorage Lake Hood float plane airport to go see bears at Brooks Falls or Lake Clarke. this is bucket list stuff. 2015 album pictures are from Brooks Falls. This is on my repeat when possible list. If flying solo, you can sometimes find empty seat price on plane for discount if you are willing to negotiate and have flexibility.
https://www.flyrusts.com/home/bear-viewing/If you like to bike ride, the Tony Knowles Trail is excellent paved trail along the bay where we have seen lots of moose
http://anchoragecoastaltrail.com/Pablo is our friend and they now have electric bikes.
https://pablobicyclerentals.com/Drive south to Seward. Make stops for scenery on way south as that will be right in right out. One of the most beautiful drives in the US.
Stop here for first glimpse of Alaska wildlife and to guarantee seeing the big ones (moose, bear, mountain goat) if so inclined. Kind of a zoo like setting but good for those that are not inclined to do the hiking to find wildlife elsewhere.
http://www.alaskawildlife.org/Detour on way to Seward to Coopers landing and either hike out to Russian River Falls (easy flat hike to river often full of salmon and chance to see brown bear fishing for salmon). can spend a night or two here and find lots to do. Smooth water float ride on the Kenai, drive the Skilak Lake Road for scenery and wildlife spotting.
https://www.alaskariverscompany.com/https://www.alaska.org/guide/skilak-lake-road-mapGlacier cruise with whales, otters, and other forms of wildlife sighting possible. Take the longest cruise you can with whatever coupon they can get in the book you choose. The more time ont he water the greater chance of finding and watching whales. Dress warm, water is frigid and the wind can make being outside very cold. take gloves.
http://www.majormarine.com/ is one group. Look for coupons in coupon books.
Can Glacier kayak here too with the best trips requiring a shuttle out to the kayaking areas.
http://www.sunnycove.com/Halibut or salmon fish out of Seward if you want to fish. If that is on your agenda, let me know and I will give you names of better boats to go on. Hike up to Exit Glacier, hike up to Hubbard icefields if you are in decent shape to do a 7 mile hike with 3000' +/- in elevation gain. Black bear, grizzly bear, moose all in the area. Great hike that my 8 year old son did.
http://www.nps.gov/kefj/planyourvisit/exit-glacier.htmhttp://www.nps.gov/kefj/planyourvisit/harding_icefield_trail.htmBest place to stay in Seward. Awesome cabins with outdoor firepit right on edge of Resurrection Bay
http://www.angelsrest.com/Best Western is another decent option but nothing like Angels rest cabins on the water. Rooms in Seward book up early so book way in advance.
two nights in Seward, three if you want to hike. You can do a glacier cruise and the short hike to Exit Glacier on the same day since it doesn't get dark before midnight. The hike up to the Hubbard Icefields viewpoint is a solid half day for those in good shape or a casual full day if you want to pace yourself and enjoy the scenery but it is a great hike.
leave Seward drive north back to Anchorage, drive east to Matanuska Glacier and go for hike on glacier with these guys.
http://www.micaguides.com/continue on to Valdez. This will be along day driving and the glacier hike is a nice halfway point. The hike out on the glacier is one of the things we have repeated over the years. Plan on 14 hour day or make reservations at the hotel near the glacier and go at a more casual pace. The drive from Anchorage to the Matanuska glacier is very scenic and the area right around Valdez is full of scenery. Two nights Valdez visiting local glacier and going sea kayaking. Our best kayaking has been out of Valdez.
Take the ferry from Valdez to Whittier and then drive to Girdwood for 1 night
take the lift to the top of the mountain at Alyeska if the weather is good. the views out over Turnagain Arm are great. If you enjoy adventure, there are paragliding tours where you run off the side of the mountain and then paraglide with a guide. On most days, the wind comes off the cold water of Turnagain Arm and blows up the face of the mountain and provides sufficient uplift to keep one aloft for quite awhile. I did this once a long time ago and it is on the list of things to do again.
http://skydanceparagliding.com/tandem-flights/There is an amazing restaurant in Girdwood called the Double Musky Inn. think Cajun cuisine meets Alaskan wildlife / seafood. this is our favorite restaurant in Alaska.
https://www.doublemuskyinn.com/Drive north towards Denali, take Denali flight up and around Denali from Talkeetna if the weather is good. Several 2 for 1 coupons available.
http://www.flyk2.com/If weather is not good or small planes are not your thing, take a jetboat tour with this operator. The flight up and around Denali and the glacier landing is a remarkable experience.
http://www.mahaysriverboat.com/denalialaska-mahay.com/dws.htmLots of neat little shops in Talkeetna which is also a train stop.
continue drive up to Denali National Park, stay three nights.
take bus tour into park for next two days for best opportunities to see the most wildlife and the best chance of seeing the full mountain out on a clear day. take shuttle busses, not worth the extra $$ for the "tours", shuttle buses to interior of park do not begin until June 1. shorter trips begin May 20. Go at least to the Eielson Visitor Center. If mountain is out, go to Wonder Lake but be prepared for mosquitos.
http://www.nps.gov/dena/planyourvisit/shuttles.htmContinue north to Fairbanks and do the Riverboat Tour and visit the Natural History museum. Downtown Fairbanks has lots of good local souvenir shops to get authentic items
http://riverboatdiscovery.com/https://www.fairbanksmuseum.org/Can do tour up to North Pole but we didn't enjoy that and thought it was waste of time and resources.
can fly home out of Fairbanks or do long drive/train back to Anchorage.
Alternative routing would be Anchorage to Seward (train possible but would eliminate Cooper Landing option)
Seward to Girdwood (train, shuttle or bus possible)
Girdwood to Whittier-ferry to Valdez (shuttle/ferry)
Valdez to Matanuska Glacier to Wasilla to Talkeetna to Denali (requires car, alternate is ferry back to Whittier and train to Anchorage, change trains to Talkeetna. misses drive from Valdez to Matanuska to Wasilla and Matanuska Glacier hike)
Denali to Fairbanks (car or train)
car just gives greatest flexibility and ability to set your own pace.
if you like hiking, great hike near Anchorage is at Lake Eklutna
http://dnr.alaska.gov/parks/units/chugach/eklutna.htmcan also rent bikes and ride 10 mile trail along lake to short hike up to base of another glacier at lake Eklutna. we like the twin peaks hike here but the first ahlf is rather strenous. There is a resident flock of big horn sheep at the top fo this hike that we have seen both times we made the hike
good Alaska hike search site here
http://www.alaskahikesearch.com/We also really like the hike up to Upper Reed Lake at Hatcher Pass which isn't far from Anchorage.
will review this when I have time and update wtih other thoghts.