The OP really described it quite well.
Just got home ourselves from the trip using our Lance 865 truck camper. We have a Cougar 5ver but opted not to take it on the Alaska Hiway. The TC allowed us to move at a steady pace at the speed limit most of the way. We drove from west Georgia kitty corner across the country to Glacier via Hays Kansas, then Cheyenne , WY. After Glacier went north to Banff, Jasper, Hinton then to the Alaska Hiway and on up to Tok, AK. From there down to Glenallen and arrived at our kids home in Anchorage.
I saw many folks hauling fivers and I think I could have made it with ours, but I am not sure I'd have made it without doing some damage. And I sure could not have done it at the speeds we made with the truck camper. We talked about it and while we missed the room of the fiver we are convinced we traveled for us with the right set up.
The trip up to Dawson Creek was fine and no problems- roads were fantastic.We hit a few rough spots on Icefields Parkway, but they were manageable. After Dawson Creek the roads were good but VERY monotonous and slow paced --sprinkled with a few occaisional beautiful sites and/or "fun with wildlife" until the Yukon. Roads were not too bad through BC ,but things were a bit more difficult through the Yukon. We yearned for a road that had been paved with Hot Mix ashalt as opposed what the routine gravel on tar surface treatment, or that had roughly patched potholes, or that was merely graded dirt. From Haines Junction to the Alaska border we had been warned about deteriorating road conditions (good info in Whitehorse at the Visitors center)--- and the advice lived up to its expectations.
The marked heaves are not a problem-- long as you do them very slow-- its the unmarked ones or the ones you can't visually make out that bite you. We hit one unmarked one that we could not see at 45 MPH thinking we were on a good stretch and we went airborne- --- talk about pucker factor! Our hearts jumped out of our chests. Luckily no apparent damage. I have no idea how we didn't seriously damage the entire rig on that one.
Along the way (before the Alaska Hiway) the roughness and vibration broke one plumbing fitting on our bathroom sink. I was able to pick up fittings at that great hardware store in Jasper before we hit the ALCAN and make a good repair.Once on the Alaska Hiway, every cabinet latch was knocked out of alignment. Upon arrival in Anchorage we found more water leaking from the TC and we still can't find the source on it yet.
In Anchorage I wimped out and told Momma (my DW) I wouldn't be driving the Alaska Hiway back-- it was not an enjoyable drive and I really didn't want to go back on the Alaska Hiway- I had enough of it. She was with me on that decision. We were then lucky enough to get a spot on the Kennicott from Whittier down to Bellingham so we grabbed the space. It cost a pretty penny but it was worth it not to drive back for us.
We poked around Anchorage and the Kenai for 2 weeks- visiting our family and Kenai sites and towns- then caught the boat down to Bellingham and made the run back home to Georgia from there. It was a good trip. there was a great deal of awesome beauty, and in our view it was the trip of a lifetime. But we don't want to drive the Alaska Hiway again and will not. Next time we will fly to Anchorage and rent an RV- or cruise from the northwest.
The whole trip took 7 weeks- about 9500 total road miles from here (we actually started from NW Florida) and +/- 1800 miles on the water.