We never carry anything in the back of the truck and even with the popup we never filled the 5 gallon water tank before venturing out. I understand about the weight of the water and both of these trailers have about 44 gallon tanks. Even with the popup we always found sites with water and electric at least. I can see us becoming spoiled by having or wanting water with us all the time if we don't check ourselves. I guess I'm so used to minimal space with the popup that I don't envision the additional weight as growing that much. I'm sure it can but we've gone so long with so little that I don't see that changing much.