Kurt--you should take some of the millions you made by selling your Brit bikes and invest in a heating system---maybe an electrical radiant heater which is only on when you are there?
Oh--sorry---I forgot --you are keeping the money to buy back into Brit bikes when you are fed up with being on the dark side ! (Brit humor!).
Richard, I took one hundred-something dollars and bought a Heat Smart Tradesman IR heater 1500W, with h-d tripod. It was sold out just about everywhere, then found one on Wayfair. So far, so good. I can move it around easily and adjust the height. You have to be within five feet or so of the single element to feel the heat, but that's OK.
You can also buy just the heating unit and bolt to the wall or ceiling, or you can get a sturdy "roll cage" with handle for moving it around on the floor. I seem to recall something about fuel and solvent vapors being heavier than air and creeping along the floor, though ... .