Re: where to get h2o
Some of the bigger truck stops, particularly Flying J. Some RV dealers, a few campgrounds might do it for free or a nominal charge, some rest stops, friends and family, and probably other places as well.
I would suggest carrying a bit of water, in case you want to stop and wash your hands, or have lunch or use the toilet. I usually carried 1 mark on the guage worth of water in my tank, about 10 gallons I think.