OP -
Your 36x36 barn build is obviously to small.
I've lived and worked for months, maybe years, in small trailers and one of the main problems was inclement weather.
Cold, rain, heat, snow, whatever. As soon as I stepped outside I had to deal with it.
All of these trailers were US Military.
A lot of that time was spent in Texas and Georgia. But several of the best months were spent in Germany.
There the command set trailers up in "Fest Tents", like beer tents at Oktoberfest.
That's partially why I suggested putting a structure inside a pole barn. That gives you space to step out of the "living area" and not have to fight the weather.
If you could increase the size of your barn you could give them a living space for a few years and then recover it when they move out.
You could even park a trailer inside the barn instead of building interior walls.
Now except for some of us over 70 there are very few on here that couldn't use more workshop space.
Now I understand the need for noise control is paramount but that might be solved by hanging a wall of noise absorbing foam board.