We did a 8 month trip a couple of years ago all around the north country (I dont think there is a road in AK or NW canada we havn't driven apart from some of ice roads
). We had a 1985 25', so its not really as big investment as your new rig, so I wasnt so worried about the stone damage. Here's just random jottings of things I learned about travel up north, a lot of it depends on what kind of trip your planning and what you want to get up to. We took just about every road, regardless of condition of the surface and spent almost every night boondocking off remote side roads, so the demands on the rig could be a bit more extreme (road to mccarthy would NOT be a good road for the whole rig). If however, you have limited time, the "main" roads still offer TONS to see and do, and even main roads up north can be a bit of an adventure.
The Milepot is really really useful, buy the hard copy and leave it in the cab of the tv. Its pretty useful. Also GOOD maps, this is not becuase you'll get lost, after all there are only a couple of roads
, but its very useful to help pick up land marks, guess where good boondocking sites are and plan hikes and other activities.
As somone above said, the Alaska hwy does have lots of open gas stations during the summer (less out of season). However, I would still say take two jerry cans (40gals) for extra diesel. This is becuase of two reasons: (a) some roads that you might venture up dont have lots of gas stations (e.g. dalton hwy, dont take the rig up that one) and the peace of mind is great (b) while lots of places do have stations , the prices can vary a lot, so when you find a cheap station (e.g. whitehorse) fill up everything
In Northern Mn I went to a scrap yard and picked up an extra wheel and tire for my truck, so I had two fullsize good tires mounted, inflacted and ready to go. Lucly I never needed both, but I did meet people on the road that had got stranded (on the road to mcarthy for example) because they had two flats.
Ahh yes, well I did fit mud flaps on the truck and a covered those expensive curved windows with cardboard . This "kinda worked", but trailer still had a lot of small stone dimples. Again I think it depends a lot on the roads you drive. I would say make sure you use very wide mud flaps, I think mine where a bit narrow.
As others have said, there is plenty of camping on beaches in AK (homer and seward both have "official" boon docking on the beeches, other places you can just ask around and find quiet spots on the beech). BUT if you go to these less official spots bring a good shovel. I got the rig sunk up to its axles in soft sand near Anchor Point and I had to dig the whole thing out (!). Bring along the usual basic set of tools.
As others have said the AK hwy is in pretty good shape these days, so are many of the major routes. The only popular roads I would not take the rig on are "the mcCarthy road" or the dalton hwy (the road up to the north slope). Thats not to say you shouldn't go there at all. We had a great time doing both drives, but we left the rig at a campsite before setting off on them. Definely go up the dalton if you have time, you see some cool wildlife (hopefully), e.g. musk ox, caribou etc.. but also you see some of the wildest parts of alaska and traveling the route of the pipeline and seeing the north slope oil town of dead horse gives you a new prospective on the politics of north slope drilling. Word of warning about that drive, it will take you more than a day to do the 500 miles or so from fairbanks to deadhorse, be prepared to sleep in your truck. I did the trip back in one go, but it was a very very tiring trip. The road up to Chicken, AK is a bit dirty and some gravel, but its fine and fun drive.
Most importantly Don't worry:
Some books you read make the alcan and the north sound like the wild west. The north can be wild, but its really not that bad. Be sensible, know how you vehicle works, take it easy and enjoy. Even if some bad happens (truck breaks down etc...), I have always found the locals to be nothing other the most friendly, helpful bunch.
Wish I could go back next spring
... have an awesome time.