Dehumidifier for TC

We always vent thru windows and or top hatch. We had moisture even under mattress prior to learning the venting thing. Do check under mattress if you have not done so.

I have the roof vent above the bed open about half way and will crack one of the lower sliding windows about 1/2". I have a Max Air cover over the vent so rain and snow don't come in.
In my tent camping days the door on the tent was open most nights in the winter.

Another vote for window and vent.

Were you opening a top vent and a lower window? This will create a very small undetectable draft and will pull the moisture out. They don't have to be cracked much, just about a 1/4" for a pass through window and 1/2 turn on the roof vent.

Also, if you plan on camping much in cold weather and don't have thermo pane windows, use 1/2" foam board in the wondows you don't care seeing through and 1/16" acrylic for the ones you do. Easy to cut and file for a snug fit. I just use blue painters tape to hold the acrylic in while the foam board is cut snug enough to stay in place.

With the foam, acrylic windows, and venting I don't have any problems down to about 0* with two people. If I notice some condensation trying to build up, I just open the window and/or vent a little more. When cooking I open up the window behind the stove and crank the roof vent another turn or two to remove the extra moisture, though the colder it is, the more I stay away from the high moisture cooking like boiling things.