I looked a lot closer at your suggested coop from post 1.
It's not bad for 4 chickens. It would need a bit of modification for your climate. Maybe a ridge vent so venting is at highest possible point and in winter the roost level vents can be closed.
The nest box design will need adjusted...
It's probably so it doesn't interfere with neighbors views....
Whatever you decide draw it up on graph paper to scale. That will allow you to adjust it and tweak it without wasting lumber.
For your needs have you thought about a walk in coop?
You get brutal winters. I would not want to have to be in the weather while doing foot checks, mite checks, treating anything or gathering eggs.....especially if doors get frozen shut.
A 4x8 walk in coop requires 6 sheets of siding. A 6x6...
I feel like it's a bit short inside for your climate.
The ventilation is at roost height so not great in bad winters.
Can you tell us what your must haves are for your coop?
Will they need to spend days closed in due to snow and cold?
Where do you want to keep food and water in the winter...