This has been an interesting thread. Lots of ways to dump the humid and insulate the shoe box. I bought some 1-1/2 inch closed cell, aluminum backing both sides insulation board and glued it to back of all my cabinets, high and low, and to all 3 front and the pass through windows with Gorilla-Sticks to anything glue. I also cut and glued insulation surrounding the propane tank compartment, which Lance failed to do at the factory, and have been impressed with the results. I think our ace-in-the-hole is that we have an old fashioned wood frame camper. We still use the lower 'secret' door on one side down low open just a bit to let cooler air enter down low and open the Fantastic fan cover just a bit to get air passing through and taking the humidity with it. We turn the heater off while sleeping, which can be a thrill the first couple minutes in the AM while standing there in your tank top. Once I get the old style perk coffee going I open the roof vent even farther and regulate more by opening the kitchen window a bit as the box heats up quickly. We have not camped in temperatures below 5 degrees F, because without heated/insulated tanks or double pane windows the whole water system would freeze into one piece: no moving parts, and has. When it gets below about 15 degrees F, and we're trying to camp, we go dry using 1 gallon containers of water stored in an insulated lower cupboard for drinking and 100%, minus 40 degree F, RV anti freeze to flush the toilet. No water in the system. Here's the total line up, of which we use only the right 3 columns:That dark green round thing is our outdoor pop-up shower enclosure we use when in warm, and remote locations using the outdoor shower. The larger ones are used when we are the support vehicle for cross country fat bike races.
When on the road, as we will be next week going down the eastern side of the Sierra Nevada to Death Valley, we pay careful attention to the temperature out as below about 15 degrees F, with the wind chill our system can freeze up quickly. You don't have much time to make up your mind. If the temp takes a sharp turn south across our freeze add 15F threshold, we will dump the tanks, fresh, grey, and black water tanks and run the pump until it's dry. Ive even used my 20 pound CO2 tank (to get the tires back up to street pressure after doing the dunes) when desperate to blowgun out the plumbing.
Keep those ideas coming. Ive learned a lot.
regards, as always, jefe