Today was a day of victory! I used gorilla glue AND remembered to wear gloves. (this is especially handy as I am traveling for business and it is nice not to have dirt glued to your hands when you're trying to be taken seriously)
I got somebody to help me kerf the first roof piece of foam. Math had told me I needed kerfs every 1" for the first 26" which is a LOT of kerfs, then fewer every 2-3 inches for the rest of the piece. Cutting a bunch of one inch kerfs on a table saw alone is hard. The piece gets floppy.

Once I got it kerfed, then we taped it in place with just a few pieces of tape on each side, and I went around the inside to check for gaps etc. It looked great. I sent my friend on her way with my car and a borrowed utility trailer to pick up her new mattress.

Then used a combination very long drywall screws and packing tape to clamp the foam in place over some gorilla glue. I took a handfull of bamboo skewers and drove them through the roof into the wall in a few places to make sure nothing slipped out of alignment. If I had more than half a dozen long drywall screws I might have used all screws.
After congratulating myself for a bit. I set to kerfing the second roof panel. It's not installed. I need a second step stool and probably a helper to get that one on. Just because it's so far over my head. I"m only 5'4".
I'll go get some pictures tomorrow, the light is already fading in my garage. I leave tomorrow afternoon for a week of out of town for work. So I really wanted the roof on for stability of the walls. I mean what could go wrong in the garage? I don't know but something right?