I live in Indiana and I started my build in march when it was still cold. my workshop (20′ x 20′) has a ceiling-mounted Dayton electric space heater (5000 watts, and 220 volts) and a wall-mounted line voltage thermostat.
the resin and hardener are really viscous below about 65F. I started out with the shop heated to about 60F and I kept the resin and epoxy in the house so they would flow better out of the pumps. however, once the epoxy was mixed and spread on the cold surfaces that I was fiberglassing, it became more viscous and a bit harder to spread.
after a few days of that drill, I raised the temp in the shop to 70 a few hours before I started a work session, and then lowered it to 60 when I was done for the day.
I’m afraid that working in the winter in a minimally-heated space won’t work for you.
my 2 cents worth.
ken