Welcome to BYC. That's an attractive and well-built coop and should be a good size for 6 birds. You should be proud of it.
However, I agree with the others in re: concern for adequate ventilation.
The usual guideline is a MINIMUM of 1 square foot of permanent, 24/7/365 ventilation per adult, standard-sized hen.
Given that the windows referenced are likely to have to be closed in the winter to keep drafts out of the roosting area and the fact that even small amounts of snow block ridge vents, this is unlikely to be adequate.
Winter ventilation is necessary because while chickens tolerate DRY cold down to 0F and below, moisture plus freezing temperatures causes frostbite. The chickens themselves generate a great deal of moisture from their breath and their poop, especially at night when they're on the roost.
This is what you're looking for in terms of airFLOW to remove that moisture:
View attachment 3114343
If you can open up your soffits under the roof overhang and open the entire gable triangle inside the run where it's sheltered by the roof that should give you the airflow you need.