They will be just fine. That's not cold (for a chicken) yet, and those are both good breeds for cool weather. Keep their coop dry, draft free, and well ventilated, and they can go MUCH lower w/o supplemental heat.
I put the thermo-peep heated pad (from when they were chicks) back in the coop for some extra warmth. They completely ignore it and really are fine without it. Their coop is well ventilated at the top and draft-free, and they do seem to prefer to hang out in there rather than out in the run when it's this cold.