Hi Womack,
I'm not sure how hardy I can say it is. It's in the ground now as of last fall. Until then was in a pot on the deck since 2009, I think. I know it has survived 20 F in a pot (just for a matter of hours)--if it was going below 20, I would usually slide it in the garage. I wanted it to get pretty big before I put it in the ground.
I haven't had a problem with loss of figs due to cold temperatures here (yet), but we haven't had a cold winter in a while--I'm north of Atlanta, but not too far. This winter wasn't much of a test, though even the 2 foot CdD I have in a pot on the deck never went into the garage. I have been known on really cold nights to string in the ground trees up with Christmas lights and throw a tarp over them.
Scott