Have you considered rotating the whole room 90 degrees counter-clockwise? This would put the speakers on the wall to the left of the fireplace. It may resolve your issues, and even sound a little better for when you are dining. You would want some absorption and bass trapping on the wall opposite the speakers, and the open wall has no reflection... but at least you would have less worries with the FP. And, you'd still retain your FP view from the couches.
Just a thought.
Just a thought.