Well, I don’t know the answer to that. RD might know though. I think I would be tempted to at least cover it with a row cover, if it is small enough, which should make it OK to 28 degrees, but I am very new to all this stuff.
Following a recent article on fig trees in the New York Times (I know, I know), I simply dropped a bucket over it and put a brick on top to hold it in place. It’s a little windy out there.
I would give that fig tree some cover if it is very young. If it is small enough just pile a bunch of pine needles around it. People who live in extreme cold regions go to great lengths to cover their trees, even mature ones. Search for some youtube videos on the subject.