I can give you some idea as to how long your water and fuel (propane) can last. I've got a smaller, 10 ft. truck camper that I carry on my 4WD, 3/4 ton Ram truck. Carrying about 4 extra 2.5 gallon drinking water containers, we could eat, drink and shower for about 6-7 days before we are pretty low on water. It carries 32 gallons of cold water and 7 gallons of hot water. The propane use for heating depends on the weather. In Montana's weather, day's in the 20's or the 30's with nights down to the teens and single digets, my Lance Camper runs through about 8 plus gallons of propane in four to five days. But that doesn't include using the generator to keep the Group 27 battery charged.
In the much warmer low desert, with days in the 70's and 80's, with nights down to the 50's or even colder, and running the built in generator every 2-3 days, I'm using maybe 4 gallons a week. The built in generator uses from less than 1/4 to not quite 1/2 gallon of propane per hour depending on any air conditioning use. It takes 4 hours to charge the battery when it needs to be charged. E

Last edited by Eremicus; 03/12/14.