If you get frost in your region, I doubt your tomato plant will survive the winter to grow again in spring. That said, I have grown a 6ft tomato plant from a 3" section of stem with roots but no leaves. After several weeks of nothing suddenly leaves started budding out of the stem. It was kept inside on a warm sunny windowsill until the plant was fully leafy and 8-10" tall. Based on that, possibly, if you could protect a section of the stem (8"??) with roots from frost, perhaps with a cover like a thick cloth, for the winter I could imagine it restarting come spring. This might be a fun experiment, but I wouldn't count on the plants surviving.
A more reliable method I know of is to collect the suckers (new growth between the main stem and branches) and plant them in the potting soil until they grow roots and then can be planted in the garden. You can view each sucker as a brand new tomato plant, an exact clone of the original. Here is a link with some more specifics on collecting suckers.
If it is cold in your region, you will need to keep the suckers indoors or possibly in a greenhouse as long as the temperatures stay above 50 degrees. The main issues will be giving the tomatoes enough light and warmth to make it through the winter. Depending on the size and maturity of your tomato plants come spring you might want to take suckers off your suckers and start some fresh plants for the summer garden. Who knows maybe you will even be eating tomatoes in February!