If you can get your hands on a cheap hard top then go for it. If you can't then a soft top can handle the winter. Just be careful because if its old it may become brittle. The stock heater should keep you nice and toasty but be smart and carry a couple of blankets and a candle just in case. When I lived in upstate New York I had a hard top and my friend had a soft top, both worked out fine and we never froze.