@jean, to close it off? If you do it yourself its cheap as hell. Just rip all the white trim off. Screw in 2x4's every 16 inches. Cut a piece of drywall to the size of the hole (you'd have to measure the thickness, but its probably 1/2 inch or 5/8). Screw it on. You might get away with just patching it but taping it would be better. Sand, primer, and paint, done. If you wanna do a more thorough job. Then you cut out the drywall from the floor to ceiling at the studs. Tape, patch, sand, prime, paint. Its really not that hard. Like a half days work. Most it would cost is around $30 not including primer and paint.

These photos don't help for this concern. We would need a single photo that shows the entire wall in question. We would need a floor plan showing how furniture will be arranged.

Thank you all SO much! Really wonderful to read your suggestions and get input. Much appreciated. And makes me feel there is potential for this space. I never considered a bigger rug, but will do so now as that seems to be a repeated suggestion. We will also take another look at the the height of that mirror on the side wall (above the mantel is a actually a large framed photo that I blacked out for this post). We did experiment with turning the dining table the other way, but it didn't feel right and seemed to block the openness of the sliding doors. And I was leaning towards an upholstered bench behind the couch (for a casual spot to sit with the added bonus of storage for blankets inside), but perhaps that would be odd? Again, thank you all. Keep the ideas coming!

So part of the appeal of RH style for me is they incorporate rustic, organic, industrial, or antique elements into a space that is mostly monochromatic but full of textures. Some characteristics of their style are oversized pieces, as large as the space allows. Large artwork over the sofa, often in black or white or an abstract. The largest rug the living room can hold. Statement light fixtures in every room. Natural fibers and neutral tones. Decorative elements that are large but fewer of them on display, often incorporating wood or metal. What about something like this for a coffee table?