You will probably need to either expand your housing or roof your run before winter. I thought St. Louis got snow??? If your run gets snow in it, your chickens will most likely not want to go out into the snow, and 9 sq. ft is not enough space for 7 chickens. Now if you find a way to cover your run safely (don't just tarp if you get snow, the snow load will be too much), they should be fine, as your run is decently sized.