Billy - I kind of remember you had one. Never knew you had a condensation problem. It's all about psychrometrics. IF the surface temperature of anything is below the dewpoint of the air that surrounds it - bam - condensation. Someone mentioned a dehumidifier which does the moisture removal by passing the air over a coil and wringing out the moisture as the coil is below dew point. They work well.
I like the idea of finding an old travel trailer or enclosed trailer that may not be road worthy, but worthy enough to winch onto my gooseneck. I have been watching construction jobs come to an end around here and asked the supervisors what are the plans for the small office trailers ? They tell me most of them are leased and go back to the owners.
My gem is out there. I just need to be at the right time / right place.