Find a OLD CHEAP trailer that comes close to the size you want..
Or FORGET about camping.
Buying or even leasing a trailer for a "one off" short term use is a sure fire way to lose one heck of a lot of money.
You will never, ever get anything close to what you paid for it back when you attempt to sell it after only 6 months. You will be way, way upside down on the loan then take a bath on depreciation.
You could easily be several thousand in interest PLUS four thousand - six thousand dollars in depreciation ON TOP OF THE INTEREST OWED.
Do yourself a huge favor, walk.. No make that RUN FAR, FAR AWAY FROM RVs.
You are better off using Motels/Hotels.