I do have 1 each. So 6 chix total. Temps are 30-40’s at night and 40’s-50’s during the day.
Temperatures aren't too bad yet, but they will need to be acclimated to outside temperatures before they can move out full time. Depending on how aggressively you lower their temperatures and expose them to outside temperatures they should be able to be out full time somewhere between 5 to 7 weeks.
The whole coop is about 32 square feet total. Roosting den is about 15 square feet. As far as running, my plan was to give them a run during the day when not home and then (if the dog leaves them alone) give them the whole yard for a couple hours after I’m home where they can be better monitored. As fara as ventilation in the roosting den, I have a door inside the outer part of the coop that can be opened for air.
I think there's some confusion in terminology. The coop is the enclosed housing where the roost and nest boxes are housed. The run is the protected outdoor area. I believe you're calling the coop "roosting den" and the run "coop," correct? I'm clarifying so we know what space you're working with. Because right now I see an elevated coop inside a run.
As far as space the recommended minimums are 4 sq ft per bird inside the coop, 10 sq ft per inside the run. If your run (what you call coop) is 32 sq ft you'd need about double that to meet the base minimum, which may or may not be enough space once they're grown. Space is a main factor in behavioral problems such as feather picking and bullying.
Ventilation needs to be available 24/7 in the coop. If by "door" you're talking about the pop door (the one the chickens go in and out of) that's too low and too small to provide enough ventilation for 6. Even in cold climates you want 1 sq ft ventilation per bird up high to let moisture out and reduce risk of frostbite.
I can give you instructions on how to convert a small coop/run combo into a larger coop-only, if that's something you're interested in. You will still need to add a proper sized run though.
One more thing, I just noticed the coop and run are sitting on some sort of wire mesh base? Chickens instinctively dig and they can get their toes caught on wire flooring. It's best to not have anything directly under the run. If you
must have a layer of wire, then it needs to be buried as deep as possible to prevent them from digging down to it.