I added a couple of haybales at my open air spots on the coop and put down dry leaves on top of the frozen bedding. That was the entirety of my preps for this cold. My group are used to an open air coop and low temps, though only a few of this flock have weathered temps as low as those coming tomorrow. I don't expect any problems as they are well acclimated.
That would be my only concern. Mine are not acclimated. It is 50 something now. That is the good thing and bad thing about here. We do not get especially cold often, so when we do, it seams bad. We live just far enough north to get a taste of it on occasion.
They are saying 15 here tonight, so I am not particularly concerned. I am just gong to make sure I keep the wind off of them.