Hi Jeff... Just saw your post. Thanks for the kudos.
It was a pickle, no room to swing pipe wrench down on left, using the little jack to apply torque UP crossed my mind as a crazy idea ..... maybe crazy enough to actually work. Yes, heard the cabinet floor make noise, and thought of bringing out some plywood, but pipe broke loose before I needed that.
Key in this case was getting enough heat into a heavy 1-1/2 inch galvanized Tee ...and not set fire to old wallpaper, studs, etc. I slipped the torch *into* the pipe far enough to only heat the Tee. When the ancient pipe-dope started to sizzle and bubble out, then, finally, the pipe would move with each pump of the jack.