Next winter, try putting them in a cool area, low light (or cover) and don't water or feed them. I kept mine in my cool basement that way - along toward the end of March they would start to awaken from dormancy and start putting out leaves - that is when I would bring them into light and start to water. Now they are big so I keep them in the unheated garage, covered with an old quilt or blanket (still don't water them until they can be outside.)

Once figs have started leafing out, they're susceptible to frost damage. You don't want to leave them under cover for too long once they've started growing, since lack of light will result in pale droopy growth. Many fig growers do the "fig shuffle", moving plants in and out of protected spots to take advantage of early spring warmth while dodging frosts.

Potted trees that are still dormant can easily handle temps down into the low 20s and even colder.