Our four, 4 month old chicks need to go outside with our two old ladies. These youngsters are silkies and sizzles, so they're still smaller than our big orpingtons. The temp at night is about 27 degrees. There is snow on the ground. We shoveled snow in the enclosed coop area. We plan on taking them at night while the other 2 big girls are sleeping. We hope they get along... any advice?