Okay, now I get the reference to a heating blanket in the other thread. I thought you were joking.
No, don't put a heating blanket out for it, it could actually get overheated and dehydrated. As long as a cat has a secure place out of the wind that is up off the floor where it can hunker down, sufficient food and water, it'll be fine. Their coats grow thicker in the winter and they gain a couple of extra pounds. They sleep the winter away. Cats are smart enough to burrow under blankets if they're really cold. My barn cats did just fine making nests in the loose hay in the winter in a drafty barn, and I'm near Philly.
A closed garage rarely goes much below freezing, believe it or not, unless you're living in the Arctic.