We traveled Alaska in our motorhome this summer (a trip I would recomment to everyone!!!), and spent eight days boondocking in the wilds of Wrangell-St. Elias NP. Thanks to a run-in with a local (long sad story there), we lost almost all of our fresh water on the way in. We made the 20+ mile run back to the ranger station in our towed vehicle, and bummed enough water from them to fill our two hard sided and one soft sided five gal water containers that we always carry with us (we boondock a lot. I have rigged a 12v bilge pump to transfer the water from the jugs into our fresh water holding tank, saves my bad back). Using the weeds for "number one" a bit, we made that 15+ (probably no more than 20 gal total) gals of water last us the eight days with no problem, and that included making several pots of coffee, and freezing a lot of ice using tupperware containers in the freezer (gotta have our iced tea and evening toddy too). Of course the weather was not real hot, which can have a big effect on water consumption...