First, don't leave your tanks and batteries there. I would change to the barrel type locks on all storage and compartment doors. The majority of these factory locks all use the same CH751 key which helps crooks. Changing lock type won't prevent someone from getting in, but they may pass on your unit. If your power cord is the type that goes into a "mouse hole", I'd put a locking cover on it. I think I would tend to leave the curtains/blinds open and make sure they can't see anything looking in from the outside (take TV out for sure). If they can't see anything of value inside, they may simply pass it by.
I think you can get burglar alarms for an RV but have not researched this. I would think that would help a lot, especially if you have a sticker on the outside saying there is an alarm.
RVs are simply so easy to break into with a crowbar or screwdriver. If they really want in, they will get in. If you have options of what lot to store it on, I'd check into the history of break-ins in the area and how well they patrol the lot (if they do at all).
Never had to do this so am just saying this from a practical point of view.
Gil & Deb & Dougal the Springer Spaniel