At Minus 5 Peter Bugsy stays in the garage. I've tolerated a sunny 30 degrees with windows up, wind blocker in place, tonneau, and heater on full blast for a <10 mile jaunt to run errands but that's my limit. And I was 10 years younger last time I did that. You Cheeseheads are gluttons for punishment. Or maybe trying to get the Morris going in the winter, same stuff applies.