You are correct in sense but when outside temps drop below freezing you will almost always get condensation no matter as the inside air moisture content will condense on the cold surface regardless of whether it is heated or not. As soon as the outdoor ambient temps drop the inside air will most likely reach it's dew point and form condensation.
I have this problem in my garage. Insulate the steel and make sure you have sufficient ventilation gaps.
As stated by Neil, good ventilation is the key