Had a sheet of plywood on the driveway, a couple more smaller ones leaned against sawhorses to represent end walls, a tarp slung over the whole thing, and was sitting inside on a pail. Trying to get the feel for just how small I could make a portable shelter that I could pull by hand. Heard footsteps in the yard, and my son peeked in at me with a quizzical look. "WHAT are you doing?" he asked. I told him what I was doing as I climbed out and saw that he was with his girlfriend. Oops! Got caught acting like a kid in front of the girlfriend, gotta admit there ain't much status in having your chick see Dad in this situation as opposed to, maybe, waxing a Corvette or something with some bragging rights. Sorry kid, maybe you can tell your other friends that you are an orphan and I'm your weird uncle who lives with you before I embarrass you further.
Seriously, though, I think 5 feet long by 40 inches wide by 54 inches high is as small as I can go to make something collapsible with enough room in it to jig, have a small (lantern) heat source, and squeeze a second guy in if absolutely necessary.