i80:
Easier to get off if need be, but only places worth stopping are truck stops
There are occasional large breaks between exits with services, but ime not much different than the turnpike. What it comes down to is will there be a bathroom when your kids need it (which is right after you got back on after the last exit, and the answer is probably not;)
I don't think there are many more areas with 3 lanes on the turnpike, but I may be wrong.
This.
I haven't taken the PA turnpike in many years so I can't really compare the two, but having driven I80 dozens of times (mostly at night) I can assure you these concerns are being exaggerated.
The PA rest stops are kinda dated but do the job when you need a bathroom stop.