We have a 8' x 8' insulated coop and 12 buff orps and six laying boxes. We hadn't planned on keeping all of the chickens over winter, when they would be more confined because of weather. Now I'm worried they're too crowded. From what I've read, 64 square feet be okay. What do you all think? On most days, we leave the pop door open so they have the option of free-ranging, but with the snow and cold temps, they're not out that much. Thanks!