For a family of (male/female) two, in a work and play toy hauler, for a week-end, we need 30 gallons of water every 3 days, and that is only one navy shower each. We do wash dishes but only eat once per day at the camper. Now once you haul the water up, you have to let it go sooner or later, and that would be where? You may think you don't need power, but the water pump requires a battery, and it is going to die without being recharged. It will die based on stereo and gas detector hooked to it, even if you never use it for lights or water pump. That's where the generator comes in.
IDEA, rent the trailer and borrow the truck for a week-end, go out there and see what you think. Don't take any water. That way after you set it up, you will have to go and find some. Now make sure on the way home, you have somewhere to dump the tanks also. Live without power and stuff for a week-end, and see if it suits you. Might be cheaper than a mistake in the long run.
2012 Ford F250 ext. Cab 4x4
2002 Jeep Wrangler Sahara
2008 Yamaha V-Star 650 Classic
2008 Work and Play 18LT