[wingnut60]

The thermopane windows will help, but they fall short of what is a double-pane window in a house--just about all Suites have the windows, but you will still have frost buildup inside if you can't control the humidity level that will climb as normal breathing is done. And if you use propane to heat the trailer, humidity is a product of that combution. Not familiar with the Espar, but I mentioned Cheap Heat earlier--you might check into it. Using electricity to heat won't add to the humidity as much as propane heat will. Having 2 sources of heat will be a necessity at some point, based on some of my WY experience--altho it is 20 years ago.
Sounds like you have a good handle on what needs to be done.
Wishing you the best of luck in getting set up.
Joe