Getting a shop that size warm would be my main issue - we hit 41 below night back, minus 39 last night, winds working wind chills down to minus 60 or lower brrrrrrrrrrr - every seam or air leak point that cold can find shows up, no matter how tight one thinks they got things .......no way I can handle shop that size when the heat bill comes due
I'd love it if it could happen. Fill it up with tools...and junk....in no time. Then want more s/f too