You can always do as I mentioned, put them out during the day and move them somewhere warmer at night, which can be smaller, this is something I do a lot, the chicks are exhausted from playing all day that they sleep all night and are eagerly waiting to go the next day, it can also help with the mental transition, they will often cry horribly if just taken somewhere and then night comes and they get frightened, I prefer a slower transition, then another week or two and they would be fine being left out.
It was 39 degrees here last night.
