: How is the Tyvec suit for "comfort" in 93F 80%RH conditions?

You'll roast. I've worn Tyvek suits on a production floor when insulating with polyisocyanurate and also in clean room environments. They don't breathe very well and I found I sweated pretty hard at anything much above room temperature. That's one reason that clean rooms are typically kept pretty cool.

Have you thought about putting an air conditioner in your garage? Even if you couldn't get the temp down, it would at least reduce the humidity. For that matter, a dehumidifier would help, if you don't want to spring for A/C.