Lived in a 19' Prowler for a while, temp job transfer. After a couple years I gave up on the temporary and bought a house.
MRE's for when you can't get to store for food. Microwave, small. Note book computer, no room for desk top. Leave the upper bunk mattresses at home, you will need the storage. The location of a hardware store for repair parts. Tool box to make the repirs. Don't forget the hacksaw for plumbing. A fan for when the A/C dies.
I you are there when it gets cold. A couple gallons of drinking water for when the hose freezes. A 1500 watt electric heater to save propane. A good sleeping bag for when you run out of propane and you loose ac power.
Good luck