Just a couple thoughts without knowing more about your situation. A little insulation and a strip or two of baseboard heat and you could have a year round work space out in your shed. It might not take a whole lot to heat the space to 60 or 62 or even 65f, cut it back to 50 at night. You paints won't freeze and neither will your own digits. I suppose it depends how big your shed is though, how long a run to get electricity out there too..
Either that or if you have a decent basement maybe move your stuff down there at least for the winter. Award winning commercial and contest winning model builder and painter Don Yost does all his work in a basement shop he set up. He has a perminent exhaust fan he set up in there vs using a booth. That's real old school but it still works today.