A rule of thumb accepted here, and while not iron clad, it is a good place to start, when considering how much space in a building a flock should have is 4 square feet per bird. So if you are going to keep 10 birds x 4 square feet = 40 square feet. So you would need a coop that is 4 x 10 or 6 x 7 feet, not inches, you really need more of a shed like building for the number of birds that you have.
Then in the north, where winters are serious, you need about 15 inches of space above their heads when they are on the roost, not 15 inches from the roost to the ceiling. And you need space away from the walls. This allows the warm moist air to rise above them keeping them dry. Dry chickens are warm chickens, but they need space to keep dry. Good ventilation is the best thing for chickens to allow all that moisture to escape.
Imagine (or remember) being in a car in the winter with several people with the engine and heater turned off. Almost immediately the car fogs up because the cold on the outside makes the warm moisture filled air of breath condense. That is what you want to keep from happening to chickens.
It is so contrary to what people need, we think warm, close up the doors tight, keep the heat in, and that turn out to be nearly a guarantee for frostbite and poor health for chickens. They will be damp if they are too close to the ceiling and to the floor and to the walls. If they are damp, they are cold.
In South Dakota, by the first of December, my birds will be roosted up by 4:00. They will stay there all night until 7:30. They will spend a large part of the day in there in a blizzard, although mine do go out as I also have shelter in the run. That is a lot of time to spend too close together - ugly behaviors develop.
So those darling coops are just not big enough for full size birds, they do not have the space. The birds are both too close to the ceiling and to the floor, and as your birds get bigger, they will become more crowded. The more crowded, the bigger the manure problem. The bigger the manure problem the bigger the moisture problem.
Two coops are not the problem, it is the size of either coop and the number of birds that you have. IMO, you need either a larger coop, as in a more shed like building, or a lot less birds. I would not want to face the winter with those coops for anything less than a possible brooder for chicks. I would keep at least one of those coops, ideal for raising chicks, ideal for separating out a rooster if needed, but not as a real coop for a flock of birds.
I hope this helps. You can cheat in the summer, the birds are still smaller, the days are long, but come the fall, the number of birds needs to fit the size of the coop you have, and you really can't cheat. This is my opinion, I have had birds for 15 years, in somewhat similar climate for what it is worth.
Mrs K