Towing the Toy Hauler with a full fresh water tank?

I always travel with empty holding tanks and a minimal amount in the fresh water tank. I can't see hauling a lot of liquid at 8 lbs/gallon. But then, I'm not boondocking like you. What I would do (if possible) is leave the tank mostly empty until you get relatively near your destination. Then fill the tank at that time. Of course, this supposes there will be a water source available. May not work all the time but it's a thought...