how many chickens...

Yes...and in your area the coop will pretty much just be used for sleeping/egg laying. They'll spend pretty much all of their time outdoors, so that's a nice sized run for that amount...

 

I am in Chattanooga and I have a 16x20 covered, electrified run, and a small coop that the 19 chickens only use for the nest boxes. A few of them went in the coop for one night last winter. They usually sleep outside in the run on the roosts.

 

Heck, with enough toys for your girls to play with (i.e. a few bushes and part of tree stuck in ground with branches and base) you've even enough space for twice that # and they'd still be happy. Rainy or blustery days they may stay under cover/in coop so with 12x12 50 girls have space enough for few days a week inside. With enough things to roost on or dig under or sun on or shade under or ...etc. 10 square ft per bird is generous without any free range.

My thought is if the bird is occupied and has the dirt bath/ digging area/ sun area/ fresh grass-foraging area then they are happy. THough any confinment unless very large will turn to dirt by them after time. But with the bushes/ tree they'd still be happy. Happy=great egg production and no canibalism.

 

you have plenty of space you can add some if you want and there will still be plenty of space