I only have to do the bottom 3.5 feet as I didn't take the whole inside out.
You lucky so & so... or did the kids outvote you on disturbing the mousies?
How about Aerogel
? 10mm thick by 60" x 45 feet only a mere $1000...
It's kinda true on the sheet aluminum already being reflective - its the zero-weight reflector of foil that keeps it shielding instead of storing heat and redistributing it. And its clean and bright, and with prodex its resistant to corrosion somehow - the pieces I cut for glass sun-shields on my truck have been kicking around loose for almost five years and the foam is dying before the foil.
Chunking in block foam is cool (or warm) - I'll probably use that on the roof. The problem with foams and a little less so for prodex is there is little sound attenuation - think guitar sounding box . That's something stuffing it full of fiberglass really helps with. Someone recently did a hybrid with fiberglass layered with something else. That looked pretty cool. I'm thinking prodex and foam for the roof and upper walls and fiberglass beneath the windows to keep things spoken inside the trailer when camped close to others, or at least better muffled.