Answer: Generally speaking, Trenton is too cold (your zip code places you in zone 6B, warmer part of zone 6, and in a sheltered microclimate maybe as warm as zone 7A, but in an exposed spot could be as cold as 6A) for growing figs. Some varieties of fig are considered root hardy in your area, meaning they will die back to the ground each winter and then regrow from the ground each summer and (hopefully) fruit. This is probably what your first plant has done. Depending on what variety you have, you may see this routinely. Keep in mind, too, that a new plant will suffer more during the first winter or two because it is not yet fully rooted and established, so it may do better in the coming years.
I think you will find the following article explains what you need to do in pretty good detail. You may need to cut and paste the complete url into your browser to make it work correctly.
Good luck this winter!
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