I went to Alaska summer of 2006. I don't have a map handy and can't remember the road names or numbers, but here's what I found from Dawson Creek, BC to Tok, AK.
The highway was great and a wide two lane highway for hundreds of miles. Somewhere below the Yukon in Bristish Columbia, I believe, the road narrowed but was fine. (I wish our rural roads here in CA were as good) Sure there were frost heaves here and there but they are all flagged so you can see them as you approach.
The section of road that was the worst was above Haines Juncion from the south end of Kulane Lake to the Alaska border. I'm guessing maybe a hundred miles or more. To many it appeared as though they were working on the road. What I saw was just sweepers, rollers and water trucks. It didn't appear to me that they intended on ever paving that stretch of roadway. It's a pretty cold area in the winter and leaving packed gavel and roadbase makes sense to me as compared to continual road repair with asphalt.
As far as protection for the trailer, I ordered that clear cover they put on new cars for shipping. The first piece I was attempting to put on barely touched it's self and that was it, ruined. It was easy to install, just don't let it touch it's self. I made the mistake of starting at the belly band and going down. I needed one more piece to cover the very bottom 1 1/2 inch. I didn't have time to get more and sure enough my trailer has some road rash in the area that was not protected. Oh, I forgot to mention I went around the curve of the trailer just even with the running lights
and that was fine. I also had mud flaps on the Jeep, they really didn' help much.
You said Dawson to Tok. If you are speaking of The Top of the World highway through Dawson City and Chicken.....I didn't go that route.
I was sight seeing so my travel was slow compared to most. I travel with a dog so I stop at just about anything to see and that gives Lily a rest from traveling and a good walk. One day I only went 75 miles, just 'cause. I spent 2 nights in Whitehorse to explore the area and take a day trip down to Skagway, other than that I only stopped for 1 night each place until I got to Tok.
It took me 7 days to go from Dawson Creek, BC to Tok, AK.
The only extra things I took for the vehicles other than their spare tires
was; water hoses, thermostat, air filters (which I changed in Tok as the roads improved without gravel and dust) and I took an extra fan belt. I figured if I had a problem with any of those items I wouldn't have to worry about locals having them in stock, if I even had a local close by. Most anyone including myself can change those items.
I was surprised that about every 50 to 100 miles I came upon a small community, usually with a gas station. That eased my mind as it's the unknown of the wide wide open spaces in Alaska that makes a person apprehensive. With the economy I wouldn't be surprised that some of those businesses aren't closed now. In fact, one gas station owner I spoke with said his business with travelers was down about 50%. This was 2006 when we had our highest gas prices until last 2008. My recommendation is top off at every gas station as the one list in the Milestone maybe not be open anymore.
I guess that's it for now.