Originally Posted by OSIN
the Airstream does not really do that well in extreme hot and cold (below 50 or above 80)
I think your temperature range may be a bit small. If evenings cool to the mid-70s, something like a Fantastic fan can quickly change out mid-day warm air for cooler evening air. The AC works, too!
We have had our Airstream in locations where the night-time temperature is well below freezing. The furnace handles that well, but does consume propane. Electric space heaters are also effective. If daytime temperatures stay below freezing, we move to warmer areas.
Our trailer has graywater and blackwater drains outside of the heated belly. For below freezing temperatures, we have installed Ultraheat (http://www.ultraheat.com/
) heating pads to the exposed pipes and valves
For hot and cold weather, being connected to shore power is a very good idea.