Not sure of how many trees you have but have you though about planting them in rows and setting up poly low tunnels? I’m going to be growing my in-ground figs as a single 20ft hedge row and currently trialing this method here for protection. Right now I only provide them supplemental heat when temperatures drops very significantly or go below 20°F, so far this year I only had to plug in the heat three times. The added benefit (I hope) is that I will be able to use the poly tunnel as a budget greenhouse to get an early start on the growing season.
I actually realized I made the mistake of planting my fig hedge row on the north side of a 6’ privacy fence - granted, at least 4’ away from it. So if anything I accidentally placed them in one of the colder micro-climates of my backyard. I guess well see how things work out come spring.