We spent 3 months north of the Canadian border and still didn't get to see everything we wanted to, but we also spent time fishing everywhere we went. Had we just looked at the sights and moved on, two months would probably have done it. There is much to see and do in western Canada as well as Alaska. Some say more.
I see you have a 26 foot motorhome, so you are somewhat mobile without the toad. Personally I think having the toad enhances the trip, but it depends on your style. We traveled a lot of back roads looking for wildlife, following scenic rivers or finding fishing holes, but except for Anchorage and Fairbanks, all the Alaskan towns are small enough that we walked most everywhere once we arrived.
2004 American Tradition; 2014 Buick LaCRosse
Homebase in the Ocala Nat'l Forest near Ocala, FL