Can cots handle the winter temps in zone 5, we can see a couple weeks of single digits and a few nights below 0. Extremes we can see would be -15, rarely do we get below that. The majority of the winter is teens-low 20's. WOuld they need supplemental heat? They will have a coop thats 4'x2'. Also if I dont supplement the lighting can all 6 stay together for warmth or will the roo's fight? The other option would be the basement.