I don't know about Sprint, but Verizon's Alaska coverage has expanded quite a bit in the last few years. You can see it here
. Make sure you click on "Broadband & V CAST" and refresh the map. The yellow "Extended Broadband & V CAST" areas in the results are high speed service, while the green "Extended Enhanced Services" are 1x areas, with a max speed of 144 kbps.
Regarding satellite TV, I know from experience that you need at least
a 30" dish to receive Dish Network up there. No under-the-dome rooftop antenna will work either. Those don't work once you get just a little north of the border with the Lesser 48.
When we lived there DirecTV had no service there, but they had it at least in Anchorage when we were there last month. I'm sure it will require a large dish as well.
It's a great drive up there. Have a good time!