How to address condensation issues in a FWC/similar pop up?

[MuleShoer]

Using desiccant collectors the the marine industry uses will help while the camper is closed up. You can place them-in low trafic areas. They are not fast like a dehumidifier but will pull moisture out. I lived on my sailboat for five years and they helped a bunch
just remember to dump them periodically

 

[Kolockum]

The only thing I found to remove condensation is a forced air furnace. Plenty of wet and cold nights in the mountains have taught me that.

 

[86scotty]

I agree. Furnace or heater. My old tent camping buddy used to sit a lantern in his tent just before bed to dry things out and then again first thing in the morning. If you can figure out how to do it safely the dry heat from a lantern will actually do wonders inside a small tent (2 man, RTT or otherwise).