DIY Sauna Trailer: From Rusty Horse Trailer to Mobile Banya

My friends and I used the global lockdown to build a mobile sauna! As always, I filmed everything and made a detailed (probably way too detailed) how-to video about the construction process.
The movie below depicts how you build a mobile sauna in 45 simple steps. Just kidding, there is nothing easy about making a transportable banya out of a rusty/crusty vintage horse trailer.
But, we did it anyway. Warning, this movie is long! Given the overall length of the production, I’ve included video timecode in the YouTube description to help viewers skip around easier.

Happy holidays Permies!

Nice job!
Have built a few mobile saunas myself.
How does that insulation do at retaining heat? My construction is 2x4” walls and insulation with a foil vapor barrier and on cold days I wish it was better insulated.