Luigi,
If your house is warm enough for house plants and you have enough light, I would bare root it and plant in a root cutting media, and grow it through the winter. Roots will continue to grow above 50 Deg. F. Because it is a small plant, the roots may die before spring if placed in cold storage. If the roots and stem are still viable, rinse out all the old potting mix and replant with the recommended rooting/cutting mix. I am currently growing healthy fig cuttings in an unheated room with a south facing window, the room temperature swings from 45 to 65 deg. F. From the posted pictures, it also looks as is the plant was root bound. The 70/30 or 80/20 perlite/peat mix worked great for keeping the roots moist without water logging. Also since there is very little stem, I would bury the cutting just below soil line.
Best of luck.