Try some of the siberian, Alaskan and russian varieties. They were designed for colder seasons. I grow them in the late fall and winter here. No freezes in the San Fernando Valley. They grow well, quickly and are very hardy. Do a google search on Tomatoes for Cooler weather.
I did just what you suggested and have many varieties for colder climates. Many are the cherry varieties though. Last year I only got Cherokee Purple (not a cold variety) that I dug up and put in a container inside. The others all got frozen on an early fall night when it was supposed to get down to 38F, but actually got down to 25F. I have started indoors a month earlier to try to get a harvest on some things like tomatoes, squash and peppers.