We have driven twice to Alaska from southwest WA. The first time in a 25' class C, the second in a 30' class C. We do not tow a vehicle. We want to drive up again after we have revisited all the other states. The drive through British Columbia and Yukon are just as scenic as Alaska is. One trip, we drove into Skagway and ferried to Haines. Then we also ferried from Valdez to Whittier. You do pay by the foot for ferries but that trip had to be made in 3 weeks total and we were able to drive the main circle route through Alaska that way. We even drove up to the Arctic Circle.
The second trip we were gone 2 months. We again drove the main circle route through Alaska but were able to get down the Kenai Pennusla and other side trips. This trip we drove all the way up to Fort McPherson in Northwest Territory. That was a rocky, bumpy road but we are glad we can say we did it. If you feel like you need to get out into the water to see the wildlife, we took a half-day bay cruise out of Seward. We prefer the independence of going on our own to see the sights we want to see at our pace, rather than in a tour group.
We are now considering a one week cruise through the inside passage to get to visit Juneau and Ketchikan, which you can't drive to.