I've been sick most of this week so I have been reading, reading, planning, re-reading, etc. What else is there to do?? Overthink things!!!!
I've been camping in tents when it got cold and woke up to a rain-forest in the tent. I understand condensation forms when 2 surfaces are of different temperatures. (that may be over simplifying it?)
Some people swear by insulation, others say it's a waste of time. Is 1/2 foam enough to matter??? How about 2"??? Does it matter as long as you are creating a thermal break??? What does it take for that thermal break to happen?? A poly vapor barrier???
What about the framing area's of a sandwiched wall? If you frame your door out with 1"x3"'s wouldn't condensation occur on these areas?
I don't camp when it's cold (unless you consider the occasional 40 degrees at night cold?). I am planning a roof vent and heat. Possibly side windows that open (if I can find/afford them).