First of all, I don't agree your room is an acoustic disaster. It's big and lends itself nicely to spacious sound. I would have dropped the M5OW closer to ear level. Nice place BTW. Love the wood-burning fireplace and nature-scape outside.
This isn't too difficult I don't think. Place a VP160OW with its wall-mount bracket on the shelf just under your TV. The only concern there may be heat from the fireplace. On the other hand, I have my active LFR1100 dressed in walnut natural satin quite close to my heat-rated gas fireplace that I use all the time and have never had a problem with the functioning of the speaker or the finish.
Avoid a bookshelf speaker turned sideways.
