Depending on ambient temps, I'd get a heavy duty propane heater(s) and 100 lb. bottles. You will be waiting until Spring to defrost frozen soil with that Reznor and placing concrete is not the time to have little heat. I've done this very job and you will want the base dry and up to temp. Placing concrete on a cold base or mush is an invitation to have problems down the road.
As my old time Mason buddy states,"the only guarantee with concrete is that it's guaranteed to crack". Taking all the steps for a good installation will prevent a lot of that.