if the question is what is the optimal temperature in the shop for boat building, i would vote for anything in the low 70's F.

it's a good balance between comfortable and the optimal recommended temeperature for MAS slow hardener epoxy (which is between 70 and 80 F) which is the epoxy i use and comes with a lot of the CLC kits. 

i am a big proponent of staying in the epoxy manufacturers recomendation temperature ranges.  though you can go lower (and i have), longer set times and other working problems start to come into play.  when you go higher, the main issue is you have to work faster which leads to another set of potential issues. 

so if  you can control the temperature, the low 70's is my sweet spot and how i run my shop.

h 

The finishes (paint or varnishes) have application ranges similar to epoxy, so the same temp applies. Low 70's is great. It's not bad for the boatbuilder, either.

You'll have a few steps - like curing the epoxy before you sand it - where it could cure faster if you could turn the thermostat up. Then turn it down when the curing is done.

Having the knowledge and tools to do your own heat pump is a plus most of us lack. I myself feel confident I can safely install a gas heater, which is what I undertook when preparing my garage a few years ago for the Waterlust kit I began a bit over a year ago.

Mitchel;, where are you located?

Knowing that 70°+ would be more than I wanted to pay for the comfort (I'm in Wisconsin so winters can be downright cold, to say nothing about the wind) I opted for a target temp of 65° before & during work sessions, 50° the rest of the time. I put off using the MAS slow hardener supplied with my kit in favor of their fast hardener which, according to their chart of pot life / cure times, wouldn't have me wishing I'd turned the heat up higher.

You have an advantage of your shop in the basement so the heat demand ought to be less than what I'd anticipated. I did insulated the garage roof & walls before I began assembly. Put a meter on my heater too so I could record its run times (somewhat skewed to the long side as it records when the thermostat calls for heat rather than when the burner's lit) to get some idea of what it was costing me. Came to about $.05/hr last November, $.09/hr in December, $.34/hr mid January when it was near or below 0* for a day.

Important things are to bring everything up to temperature before you begin work, don't try to apply epoxy when it's too cold as it won't 'wet out' wood fiber or fiberglass as well as when properly conditioned, don't let temps fall too low after work's done or you'll extend cure time. Oh and keep your resin & hardener(s) conditioned to your working temperature before mixing. Heat lamps are useful for putting moderate heating on areas you feel need a bit of help with too. I bought two 250W flood lamps and the clamp-on fixtures they're used in for poultry-raising. Served me well.

   Thanks everyone for the tips. Much appreciated. Hopefully I can help others when I get some experience myself. To spclark, I live in east central NY and it can get very cold here as well. Stay safe all and happy holidays.