It depends what kind of chickens you want to raise. We raise/breed silkies here, and coops are heated to 40F.
Our farmer neighbor raises Brahmas and a couple of other larger breeds and just has a not-so-great coop. She loses a couple every year.
Never go with a prebuilt as three days in this wind; it'd be on the ground. I would look on Marketplace for an old shed or ice fishing house. The latter are usually insulated, and remodeling one to be a coop would be pretty easy.
Insulation is a good idea, with no drafts, but you'll also need ventilation. You would get some ideas if you perused our Coop Forum.