I live in Minneapolis, MN where it gets into the negative degrees F. regularly every winter and I have never found that to be a reason to use glass. As long as your house is heated (which I assume it is) a screen enclosure would be better.
Edit: I just read: "What if all I can get is a glass terrarium?" Why would that be the only thing you could get? My honest advice is if that is all you can get, don't get the chameleon. Chameleons really do need the ventilation (but not a blowing fan) and the height of a screen enclosure. There are literally hundreds of websites that sell screen enclosures online, you could easily find one.