It will be tight but you can make it work. The roosting bar however looks too close to the wall. The girls need about 15" from the wall. I would do 2 short roots so they have the full length of hop down
Build a nice large secure run with a roofed section that they can access first thing in the morning. Food and water outside and just keep your limit to 6.
You are in Maine, thanks for providing that information, it helps. Based on that alone I'd say yes, they will need more room this winter.
I did not say you needed a bigger coop, I said they will need more room. Chickens don't know the difference in coop space, run space, or free range space. They just know they have it when they need it, wherever it may be. I try to look at their "space system" instead of breaking it into individual components. It's up to you to manage them in a way that they have access when they need it.
That looks like an elevated coop. Did a run section come with that? If so how big? That may help determine if that is enough room this summer. If it has anything you should be OK for the summer. You can follow the link in my signature below to get my thoughts on why space is important. I don't believe in magic numbers as to how much square feet you need in the coop or run, we all have different circumstances, like your climate. But in general I find the tighter I pack them the more behavioral problems I have to deal with, the harder I have to work, and the less flexibility I have to deal with issues.
Chickens hate change. If a chicken wakes up to a white world after an overnight snow they probably aren't going to go out in it for a few days, pretty much locked in the coop. Run space is not available. Also, mine go out when the temperature is below 0* F as long as it's calm. I don't see much below 0* F so I don't know what that limit is. But if cold wind is blowing on them mine are not out there. A nice breeze is comfortable in a hot summer but a cold wind is "not no how, not no way, I ain't going out there" in winter.
If you can provide space outside that remains snow-free in winter and provides good wind protection, you will probably be OK. Some people count on shoveling out their run when it snows but that's not always easy when a blizzard is blowing. You might be able to cover you run in a way that keeps snow and cold winds out. Some people use heavy plastic like a tarp. In a way the run becomes part of the coop in winter.
If you do try to enlarge that coop instead of providing more usable area outside, I'd at least double it in size. If it is an elevated coop that probably will not be easy since you need to be able to reach all inside areas.
I’ll great information ! I plan a 6x12 ft chicken run.
soinds like I need to double my coop
Does the ceiling height matter?
If I enlarge, there will be two sections with different ceiling heights.
The chickens won't care about the ceiling height (that's more for human convenience).
It'll be a tight fit in there but at least there'll be enough roost space. Going to be difficult to expand the interior space so not sure what to suggest...
What we did was add on a covered, predator proof run. We put plastic around it in winter to keep snow out and as a wind barrier. It works perfectly. We live in northern Michigan so it gets very cold (-30s sometimes) and is very snowy. My chickens almost never go out all winter. They sometimes will.walk along the shoveled path, but really dont like it. What about adding on a covered run instead of changing the coop you already have?