Our truck has about a 200-mile range on gasoline (we don't have a diesel) when towing our TT. So, on our Alaska trip last summer, we topped off every 125 to 150 miles. We drove the Cassiar, Stewart, Alaska, South Klondike, Haines, Tok Cut-Off, Richardson, Edgerton, Glenn, Seward, Sterling, Parks, Talkeetna, Taylor, TOTW, and North Klondike highways without even a gallon of extra fuel. Never ran out or even got worried that we would. Of course. that meant we paid the local prices (very high to outrageous) in remote places like Chicken, Pink Mountain, and Muncho Lake.
We did not drive the McCarty Road in our truck. We took a shuttle van from Kenny Lake to Kennicott and the shuttle driver had a flat on the way up. But that was not our only experience with flats. If you get a screw through the sidewall of a trailer tire, plugging doesn't work--just ask me. And 8 plugs in one tire is usually a good sign that it needs to be replaced. So, we bought three tires along the way--one trailer (2012 w/ 4,000 miles at the start of out trip), two truck (2011 w/ 18,000 starting miles).
My advice--take good spares for each vehicle, a couple of cans of Fix-A-Flat, a tire plug tool and plugs, a small 12v compressor, leveling blocks to raise your trailer high enough to change a flat, and your tools.
I had all those items and they enabled me to get to places like the Whitehorse Walmart to buy tires instead of getting them in a place as expensive as the Dawson City NAPA store. And I used my tools a number of times making minor trailer repairs that I couldn't have made in the middle of nowhere without them.