From someone who has driven the ALCAN (Alaska - Canada Highway) multiple times, albeit never in an RV. Yet.
Don't even think about a trip from Outside through western Canada to Alaska without a current version of "The Milepost" at your disposal. Packed to the gills with information on places to stay, places to see, what to do, where to find fuel and services, grub .... on and on and on.
Use it to plan your trip - use it adapt to changing plans on the ALCAN - and plans ALWAYS change on the ALCAN. Information updated annually, and you can supplement with the "drama filled FB group" for late-breaking news.
Best $40 you'll ever spend to support a trip like this - https://themilepost.com/about-us/