I run a dehumidifier in my camper all the time when it is home. The drain hose is a small diameter clear vinyl hose. I extend it to the outside at the corner of the slide. It will fit through there if the slide is open or closed. There is little humidity during the winter, so it does not freeze. It removes a lot during the summer, but by just passing it through the edge of the slide seal I don't have to worry about filling my tanks with water from the air.
2013 Silverado 2500HD LTZ CC 6.6L Duramax Diesel
2014 Sunset Trail SF270BH
Holly & Buster, mini Dachshunds
2016: 1 trip, 3 nights in 1 state, 316 miles
2015: 5 trips, 18 nights in 3 states, 2707 miles
2014: 5 trips, 14 nights in 3 states, 2426 miles