T-Mobile roams on local Alaskan carrier GCI without issue in cities (towns?). Coverage is, admittedly, better than I expected.. You'll hit some areas without data coverage in between cities. And some of those areas just don't have signal at all.

Fairbanks is a 6h drive from ANC and even longer by train. Some areas toward the Kenai peninsula are in "day trip" range - including the Alyeska mentioned above.

Can't comment on fishing.

I didn't spend any time in Anchorage to see their museums - I went to Denali, Alyeska, and Seward instead.