Well, instead of sitting on my duff this winter, I decided to close in the 12x18 "exercise room/stairwell" end of the garage with plastic sheeting so I could get some work done.
First I installed the remaining 2x10x20 attic floor joists, 2x10 blocking, and then put 7/16" OSB down on that end and covered it with a large tarp and two layers of 6 mil plastic. Then plastic around the front side of the building, the left side, of course, and also both the right side and inside the garage.
All that plastic does block the wind, keeps the rain out, and with the new kerosene heater pumping out 20,000 BTUs, long underwear, and a couple layers of clothing, it's reasonably comfortable in there.
The floor joists are 2x6s 16" o.c and there's 2 "sets" with a common double 2x8 header in the middle of the room. The OSB flooring is not attached yet, I just laid some of them in there to have a smooth work surface. Also, the green tint is Copper Penthanate which is a termite proofer as I ran out of 2x6 pressure treated for the blocking and didn't feel like going to Lowes to buy just one 2x6 PT when I had several untreated 2x6s on hand.
The pics make it appear the joists are ground level, but they're not, there's about 6" or so of space between the joists and ground level. I'll put 6 mil plastic on the ground then lay 1" polystyrene panels on top of the plastic which will give the floor a R-3 insulation value. Not a lot, but that's three times better than nothing at all between the floor and the ground.
There will be a non-supporting wall to separate the garage area (to the left) from the exercise room (to the right). On the bottom left you can see the 2x4 "plate" I sandwiched in to give the wall's bottom plate a nailing surface.
Just trying to do a little each day and I figure eventually I'll be able to stand back and say, "It's finally done!" But, that's still some time off... way off.