I have the mushroom vents and vent fan from CLC. I also installed a 12 volt small fan which is mounted in the cabin on the galley wall . For heat I have a 110v small space heater ($20 type) that will overheat the teardrop in about 3 minutes.
No insulation on the floor . If I need either AC or serious heating and insulation, I have made a serious error in planning ; -)