My chicks are 4 weeks and are out growing their plastic tub. I have an outdoor coop but since they are not fully feathered I don't think that I can keep them warm enough yet as our highs are in the 30's. I have 7 EE mixes and was thinking about using a fridge box with trash bags to help water proof the box. My question is should I lay it on its side and cut the top off for more floor space or vertically so they can work on roosting and have more area to jump and fly? Thoughts?