Take it Slow
As many others have mentioned, taking it easy will be your friend. I have driven the highway to/from the "Lower 48" more than a dozen times during all seasons. I have driven both cars and trucks, towed cars on trailers, and towed enclosed trailers. One trip was from Seattle to Kenai during November driving my wife's MG Midget convertible!
You will find heaves year-round. You may find construction year-round. Just drove up from Portland, Oregon in January via the Frasier canyon, Cache Creek, Fort Nelson, etc. I prefer the Cassiar as it is flatter and about 100 miles shorter from that direction but weather did not permit that way for the last trip.
The worst spots for road comditions, even as long ago as 1974, I have encountered are between Destruction Bay and Beaver Creek, and on the Tok Cutoff between Tok and Gakona (Glenallen). The worst tractor-trailer traffic these days occurs between Dawson Creek and Fort St. John.
It's a great trip when you take it slow.
If you get to the Kenai Peninsula you can drop us a message.