We have a camp shower we bring that is beyond crude on the 1st day, slightly offensive on the 2nd, and downright luxurious on the 3rd.
Our jeep trailer has 2 deep cycle marine batteries, a shower pump from an RV, and a 42 gallon water tank we keep full. The average shower consumes about 2.5 gallons of water and you don't need to hurry.
For Thanksgiving, we try and bring a few extra jugs of water to accomodate everyone's needs. Water is only 20 or so minutes away should we need more.
So, quit worrying. Oh, the shower heater is a double coil of copper tubing 8" tall and 4" in diameter on top of a high efficiency turkey fryer burner and we bring 3 of the Bar-B-Que sized propane tanks.
The shower itself is a Cabela's shower tent with several amenities for privacy and clothes changing. Basically walk in, zip the door shut, undress, unzip the side window and hang your clothes and towel outside on the provided bar. Zip closed, shower, open the window, grab the towel and dry clothes, dry off, dress and enjoy.
We may be heathens, but we do enjoy a nice hot shower in the dusty desert.
In case I didn't make it clear, it's the camp shower for anyone who wishes to use it.