We usually travel the back roads. Back roads do not have low fuel prices because there are not a lot of fuel stops, sometimes not even one in more than a few of the out of the way towns. Also, gas stations are time wasters. I would much rather stretch my legs at a park or rest area.
There are areas of the country were, especially in the winter its common to see 50 miles between stations and even up to 100. Also, at night a lot of small stations close at 10:00 pm and they may or may not have a card reader after closing. Frankly, not knowing the territory, I would prefer not to stop where there are not a lot of people around, well lit etc.
When I was flying a lot, my aircraft had the biggest tanks available, including aux tanks. More fuel the better.