You should easily be able to find ridged silver coated foam insulation boards (not real metallic silver) in Canada, at most any commercial lumber yard, building supply houses, or Home Depot. - Millet

I will try and if it doesn't work so well i will just turn it into a 3 season house and bring them down to the basemeant when I can know longer heat them well and it is too uncontrolable. Thanks everyone for your help.