I wonder if you would maybe be a lot better off either planning for a plastic-covered run in winter, or building the largest coop you can afford, since you are in North Central PA which can get snowy and cold for loooong periods in the winter.
Even just 4 sq ft per bird is going to get awfully tight, I think, if they end up staying indoors all day every day for a good long while. It's just *asking* for problems with them trying to disassemble each other.
Personally I would really not plan for anything less than 4 sq ft per bird but I think you and your chickens will have a much better time of it if you can get more like 10 sq ft per bird in coop and semi-enclosed run *combined* (which could be something like an 8x10 coop plus a 10x12 or 8x15 roofed-and-plastic-wrapped-for-winter run). At *least*.
JMHO,
Pat