Dee,
It sounds like you may have Abutilon pictum 'Thompsonii' which is only hardy to Zone 9 (that's about 3 zones warmer than your area.) See this link for photos:
Abutilon (Callianthe picta 'Thompsonii')
I'd recommend digging it up and potting it before you get a freeze. Also, check it for pests before bringing inside. If you have a glassed-in porch that always stays above at least 50 degrees F that would be a perfect spot to overwinter it. If not, a cool room with a bright window would work. It may loose all of its leaves again when it experiences the climate shift between inside and outside. This isn't unusual and it will regrow new leaves quickly. If you get worried that it may have died, you can scrape a bit of the bark with your fingernail and see if it is still green under the thin layer of bark. If so, then it is still alive and just taking a rest. Water it as needed and keep an eye out for pests like mealy bugs and aphids and you should have no problems. For watering, it is important for the Abutilon to never get totally dry and badly wilted, since they don't always recover well from that in my experience, but you don't want to water too often and keep the soil soggy either. It is best to water the soil thoroughly when you do water, even allowing it to soak in a saucer for about 30 minutes, and then not water again until the soil is dry about 1 inch below the surface of the soil (or if the leaves are just starting to wilt a little). I've found Abutilon, in general, easy to overwinter on my glassed-in porch (zone 7b/8 here.) They usually continue to bloom inside throughout the winter too, which is always fun!
Best of luck!