It has been between 19 at night to 40s in the day. It is generally in the teens only one night in a row and most days when it does get cold at night it is in the 30-40s in the day. That being said, this past week has been a bit colder during the day. I keep my 2 pairs of seramas in cages in the barn that has LOTS of ventilation (door partly open to allow other critters access to barn). So the temps in there are only slightly warmer than outside although they don't have to deal with wind blowing to much. They have straw in their cage right now and seem to be doing perfectly fine.
I just have to watch their water and unfreeze it several times a day. The other chickens and ducks that have a large open pen and access to the barn, coop and several shelters have two heated water sources along with their normal water supplies.