Personally I think 2 mirrors is plenty, but I love artwork and think it adds a lot more interest and color than another mirror. I rarely say this, but I think your husband is right this time.

Check out the artist Brit Bass Turner -- her prints used to be on Etsy, but now she has her own shop/website. Her art is abstract, prints are relatively inexpensive, and the colors she uses go with everything in the pics you posted above. Hope this helps! https://www.brittbass.com

No, I don't think it would look awful. I love big art pieces. The important thing though is do YOU like it? It's your home and it's important that it please YOU. Looking at your picture, I'm wondering if the art above the sofa isn't a tad big for that wall. (I really like it, btw.) Usually, the eye appreciates some breathing room around art. If you have painter's tape, try taping out that canvas' size above your couch and see just how much wall it covers. That might help you visualize its negative space better. Good luck and enjoy the process!

Thanks everyone. I agree on the drapes, they came with the house - don’t love them. But the in addition to the two windows on each side of the fire place there there is a very large window on the walls to right and the left. So this will be quite an expense that I was trying to avoid. But definitely an option and would do in a similar way as @BeverlyFLADeziner suggests. I also agree with a chunkier mantel, however the mantel replacement will require additional stone work, so unless I can modify what I have, vs. replace it - that is not an option. I will definitely keep my eyes open for Art, you have sent some great suggestions that I like a lot. I don’t think I will go with a mirror, as I had one up for awhile and hated the reflection.. as some has commented could be an issue.