: Can I do fiberglassing work if I heat the garage for a few days?

Why not? I've built in a basement at our cabin, and it's basically unheated - gets pretty chilly down there. I've had good luck with 'tenting' something over the kayak, then using a small heater - or in one case, a hairdryer - to keep it warm enough to get the epoxy to cure. It may take a little longer, but it can be done...