We finally got the bigger coop done and we would like to move our chicks that are 5 weeks old out with the big girls. We built a broader area for the chicks in the coop. It's a 4 x 8 area, the walls are 3 1\2' high and lined with cardboard to keep out the draft. The top is covered with wire the keep the big girls out. They will have access to heat lamp and heated water. The temp last night went down to 9 F. The chicks are currently in our basement with a heat lamp at about 55 F. Will it be OK to move them out to the coop? There are 25 of them and they are cold hardy birds.