Grow them in pots

They were in pots! In my attached garage. It got so cold this past February that it killed all 3 of my fig trees.

That's unfortunate. Do you happen to know how cold your garage got?

Yes that is unfortunate. Most garages even if uninsulated generally stay above killing temps even during severe cold. If it's an attached garage it may help to keep the plants nearest the wall that is shared with the house. It's probably a few degrees warmer there. If it's detached you may be able to use a small electric heater on those really frigid days just to keep the temps for dipping too low. Lastly, and maybe the best idea would be to wrap the fig plants with some type of insulation similar to what you would do if you had them in the ground. Unless you lived in Siberia I can't imagine wrapped insulated fig trees overwintered in a garage could get cold enough to die back.

One additional comment.......Did you keep the trees watered during the winter? If not that could have been the reason they died. They don't need much water and shouldnt be sopping wet. But you can't just forget about them and let them dry out completely. A little water once a month would probably suffice.