From Banff to Valdez is longer drive than you think especially pulling a 44ft 5th wheel in the mountains.
Banff to Jasper alone is 4hrs no stopping in a car, and with all the sites to see you pushing it to make it in 5 days let alone 2 to 3.
Get yourself a MilePost travel magazine which is the size of a large phone book. They have every campsite, points of interest along the route and small maps on pages that show the area your traveling in.
Amazon sells them
If your using Google to give you how long it takes to get from point a to point b, they are never correct in the mountains especially pulling a 44ft 5th wheel.
Banff to Jasper to Dawson Creek to Whitehorse is 5 days pulling my old 23ft 5th wheel.
In my opinion from driving my 5th wheels ( largest was a 35ft) with a diesel truck your looking at least a week Banff to Valdez even that is pushing it with little site seeing in Alberta, BC & Yukon.
You will also need to fill out a ArriveCan Application ( App) fir entry into Canada.
ArriveCAN InfoHope this helps a bit.
Soup.