Zone 5/4 is too cold. Lowest I'd try is zone 6a. Which I am in right now, even in my zone I would have to harden it off. I can't put a 1 year old sapling and have it brave -5 degrees. Look up cold hardy fig varitys, it should give you and idea. My best bets would be Bethlaham Black, Marsellies Black VS, and Hardy Hartford