SF, can you share what you are planning to bring along in terms of clothing? I read that you are always supposed to be prepared for rain and cold.
Apparently, lots of mosquito spray and even head bug nets are needed in Denali, I'm not sure what that is like in and near Seward but you might want to look into it.
I'll have specifics at the end of the week iy"h, but for now the plan is quite simple: regular clothing as the first layer (and no special underwear), a warmer layer (wool sweater or jacket (NOT cotton), and an even warmer layer (heavier wool jacket). I'll pick up rain gear in Walmart in ANC (coat, pants, and hat) and always keep those handy.
Also taking warm waterproof boots, gloves, warm hat, sun hat, and sunglass (vital on the water and glaciers).
As far a mosquitoes go, simple repellant should do the job, no need for nets where I'm going AFAIK. (Mind you, according to what I've read, the only place in Denali you might need a net is in the Wonder Lake area. But then again I didn't do too much Denali research.)