Let's assume the OP had electricity for say 6 hrs/day. running a compressor driven dehumidifier for that length of time will likely solve the condensation problem. It may take a few days but should help a great deal. Mine will often pull 2.5 gallons out of the air in 6-8 hours. Once it gets the humidity down to the 50% range or so, it pulls out about 2-3 gallons/day.
Long term use in other than a very dry climate IMHO pretty much means measures to prevent moisture buildup. In moderate humidity climates, opening windows, fans on etc. when cooking, showering may be enough. But when humidity rises outside and/or it gets cold at night, that is often not enough and a compressor driven dehumidifier is appropriate.
IMHO the peltier devices or damp rid type are fine for storage, but can't pull near enough moisture out when trailer is in use.
