Never driven the Alcan in winter but I've heard people say it is better. I have driven most of the roads in Alaska during the winter. It'll be dark almost all the time, good to replace your headlamps if they are very old. Traction will be better than you expect. At -50 it is just like dry pavement, almost so at -40. You could wait a while for another vehicle to pass by so make sure you can keep yourself warm. When it hits -40 the cold is totally different than just a few degrees warmer. Don't abandon your vehicle if you do break down, stay close if not in it. Carry 10 or 15 gallons of extra gas, some stations close for the winter. Never, never ignore your instincts because you think it's being too cautious. You feel like you should stop early or hole up in a lodge for a day...you do it. I'd plan on taking 2 weeks from Vegas.. Keep an eye on the weather, there are whiteouts and ice fog and believe me neither is fun. Probably better to come up through WA into BC and stick to the Alaska Hwy rather than the Cassiar; there's way better services. Enjoy Alaska! Oh, yes carry chains, but put on studs.