I'm in SE Wisconsin and our spring temps have been ridiculous! My black austrolorp chix are 4 weeks old and I can just now see the feathers on their heads are starting to come in (rest of feathers are in). Our night time temps are STILL below 50 degrees. (forecast says nights will be mid 50's by the weekend) I've got a great little chicken tractor that I want to move them to until they're big enough to join my lonely hen in her pasture. The roosting area of the tractor is about 2.5 x 3 and there are only 5 chicks. Will they be warm enough at night if temps are in the upper 40's? Mid 50's? The brooder is getting a bit crowded and they're emptying their little waterer almost daily!