Our house came with an "enclosed patio," complete with AC/heat, so it's just another room - which we've turned into a sun room. However, there are outdoor slider windows which go from the great room into the sun room. We have considered and eliminated numerous fixes, such as: removing the glass and keeping the holes there (but then house sounds travel into our master, too loud); removing that wall and making the great room one big space (but we love having the special sun room separate); filing in the windows and just having a wall instead (but the windows provide much needed light and we like being able to see into the back yard).
We are also planning to put a corner fireplace to the left of the windows (in the first pic, where the bookcase is now), with floor to ceiling stacked stone to match our walls outside. Furniture is from our old house and will eventually be replaced.
I think just having window treatments would look weird, and am open to architectural fixes.