Battery & water conservation is important so use as little lights, water pump and inverter power as possible.
We use battery powered lanterns and flashlights for light.
Take a Navy shower if needed. http://en.wikipedia.org/wiki/Navy_shower
Use paper plates and plastic utensils and cook over the fire to keep from having dirty dishes to clean.
Use ice chest for drinks to keep the refrigerator closed as much as possible since it uses 12 volts for the control unit.
You can charge the battery by plugging into the tow vehicle and let the engine run if the TT battery goes dead.