Rascal and the others seem to have answered the OP's questions in good fashion. The only thing I would add is to take a small air compressor and some tire plugs with you on your trip. I carry them on all long trips, be it to Alaska or elsewhere. (except for the one time I really needed it for a flat on the Top of the World Hwy. Even a spare tire that is not mounted will give a traveler a way to get a tire fixed. Fixing/mounting a tire is normally not a problem in the norther parts of the Alaska Hwy, but locating the correct size at anything approaching a reasonable price can be a problem.
I like to get out of Florida about mid May to the first of June. We normally figure on about 10 driving days to get to Fairbanks. With stops thrown in, usually works out to be about two to three weeks getting there. Have done Anchorage to Houston, Texas in six (6) days before, solo in a car, but that is a bit of a rush and I don't recommend it. LOL You have to run 800 mile days to do it. Aw, but to be young again. LOL
On any of our longer trips, such as to Alaska, we take one day during the week, off, to take care of house keeping chores, such as getting propane, shopping for a week's supply of groceries, doing laundry, getting an oil change (if needed), washing the rig if needed, and just checking the RV from top to bottom .
Takes the feeling of being rushed, out of the trip.