I am located near Chicago so it does get cold.
I would not worry about your cold for chickens any more than I'd worry about that cold for the wild birds that overwinter there. Their down can keep them warm. But Chicago is known as the Windy City. That is where your danger is. A cold wind can ruffle their feathers and down which negates the insulation. The insulation comes from tiny air bubbles trapped in the down. During the day they need places they can move to so they can avoid the wind. You do not want a cold breeze hitting them on the roosts at night.
The pictures are of a coop I am considering. It is not premade but is priced reasonably.
Personally I would not have a coop elevated like that I could not comfortably get under. You'll have reasons to reach under there. I don't like crawling in chicken poop. I'd either raise it enough for me to get under or drop it to ground level.
It is 8x20 with the coop being 8x8. I thought the coop may be a little small.
In general I agree with Rosemary's comments on space. If you follow the link in my signature below you can see some of the things I consider.
What would you recommend be changed?
I also question your ventilation. Your goal is not to keep the chickens warm. Your goal is to allow the chickens to keep themselves warm. Stopping cold breezes from hitting them is part of this. Ventilation is part of this. Your chickens are much more at risk form frostbite than they are of freezing to death. You are from that area. How do you protect yourself against frostbite when you step outside, other than protecting yourself from direct breezes and wind chill?
If you step outside with wet hands or a wet face in really cold weather you are in danger. So keep things dry. Moisture can come from their breathing and their poop as well as water in the coop. Ventilation allows moisture to escape yet you do not want a breeze hitting your chickens. There are different techniques to achieve that but the simplest to me is to have your ventilation high over their heads when they are on the roost.
The wild birds can move around and find good conditions. Chickens trapped in coops and runs can't do that.
I have plenty of space for them to range with 10 acres.
In the winter when snow is covering the ground or in the middle of a blizzard? All of that room is great when it is available but if it is not available it might as well not exist. I personally don't believe that strongly about square feet in the coop or square feet in the run. I don't think the chickens can tell the difference either. If your run room is not available due to cold winds or snow, it is not available.
I find that when I crowd them I have more behavioral problems to deal with, the harder I have to work, and the less flexibility I have to deal with issues. My life is easier when I give them more than the absolute minimum space. That can get expensive so you need to balance it.
Good luck!