I"m in the same situation here in Indiana. It actually snowed last night. I have four chicks, born 2/17, so a little over 4 weeks. They are about 80% feathered out. I have them in my guest bathroom. They are also getting a little squirlly in there, but it seems too cold outside. I have a full size coop, but nothing for the interim period. I am thinking of getting a wired crate so I can get them used to being outside, but this week our hight temp is only 40 degrees. They have an indoor temp of 80 degrees, so it still seems drastic to take them to the garage.