A wench could be very useful - if you get stuck, you'll reduce your chances of being stuck for a long time. You'll probably still need help though, because the only way you are likely to anchor it is to another vehicle (with a lot of cable). If you find a local, they will almost certainly stop to help for as long as it takes, no matter how many hours that is.
Just bear in mind a couple things:
1. If you get stuck in muskeg, you'll need something very heavy duty to get out - a regular tow truck is probably not even going to be enough. Muskeg can be hard to spot, so be very careful.
2. If you go too far off the beaten path, finding anyone to help may be a challenge. Outside of Anchorage (300k), Fairbanks (31k), and Juneau (30k), and Wasilla (11k), there are only about 20 towns with more than 1000 people. This is in a state 1/3 the size of the rest of the country (bigger than Texas AND California AND Montana combined).
3. There are far fewer places to get off the highway than I thought. There are stretches of 100 miles with no dirt turnoffs. When you find a turnoff, it will likely become impassible to any vehicles within 2-3 miles. That said, our best adventures involve exploring these areas.
If you plan to get off the highway in Alaska, I recommend something like this: