I worked on a ski resort in Utah, the building department had specs on allowable temps to pour in plywood forms. I think it was 25 degrees F and use insulating plankets over everything asap . I don't know if they have specs for ICF 's yet since icf's are a lot better than blankets. I have burned straw bales all night when we poured with plywood and got an unexpected cold snap.

How about get a junk LP water heater (one that started to leak),[FREE AT ANY PLUMERS DUMPSTER] a garden hose{$10 each 50’} and a $30 1" pump. Just pour the hose in the footer. Pump water though the water heater in and out of the hose you have in the footer. Don’t turn it off until you are back filled and have the no frost problem. 100 lbs of LP will go for 2 days with water at 65*(for me it did) With no psi on the water heater it will not leak (or not leak that bad) and you get heat to the footer that will go up the icf wall. When you are done with it all you can just cut the hose off and throw away the water heater. All you lost is a garden hose and the LP you burned. This is a cheep and easy way to keep the concrete warm and the frost a way.