[Shifty]

I have 2 I ideas that might help.

The first is a 2 tubes filled with some sort of desiccant you can push through air through. While one has air from the interior of the car going through it the other has hot air passed through it from the waste heat of the engine. Not exaust just heated air. This will dry it relative to the local humidity. When one is saturated then the air flow switches and once the new hot dry tube comes down to local temperature interior air is passed through it.

If you can be near a outside plug then a very small ac unit might be used to precool your vehicle using grid power. That will help reduce that initial heat blast.