Ox,
Not a fellow answering :)
-15 is almost always a death sentence for any figs trees, unprotected but..............
give those figs time!!!! they may have gotten colder where they were and still deeply sleeping, take fingernail and lightly scrape bark, if you see green, you know is alive, as far as frosts goes, when it is going to frost, you must bring them inside if they are leafing green out, even small buds can be zapped by frost or very very cold temps, you must do martins shuffle to protect at this time of year, if you need help, ask someone to help you. HOpe you are well!