Black Dog
Makin' Beer.
Exactly - my notes say the upper Dalton was 240 miles without a gas station. There is one enormous mountain pass where you'll be burning lots gas, but other than that it's a wide, flat gravel road. The speed limit is also only around 40mph, so you'll get good mileage.
As for camping - I would highly, highly, highly recommended it. The whole reason to be up in Alaska is the amazing scenery, and being "out in it" is the best way to experience it. You'll see a lot more cool stuff, and save a ton of money. Also, you won't have to stay in towns, which is always my preference.
Also remember the sun will be up from ~4am to ~1am, depending on what time of year you come and how far north you go.
That being said, be prepared for horrendous mosquitoes - at least a thousand times worse than you can even imagine.
-Dan
I'll bet gas is expensive out there just because its the middle of nowhere, so you might save some money by bring cheaper gas from Fairbanks. When you think about it, you'll have 10 gallons on the sides, 10 gallons on the back hatch, and 10+ gallons on the trailer. 30 gallons or more of spare fuel plus your full tank should take you a long way. Is an LJ a 20 gallon tank or is it smaller? That should get you close to 600 miles at 12mpg.