I'll start off by saying I really don't know too much about this 1 speaker surround stuff, though it does look like it might need more to bounce off of than your room allows. Still, check out Yamaha's website or better yet, contact Yamaha and explain the situation. See if they can give you advice. I'll have to admit, 1 speaker and a sub is as uncluttered as you can get for surround, and it sounds intriguing.
One other thought that I'm sure you've thought of already but I'll say it anyway...have you considered getting a good 2.1 setup instead? I don't know if "the boss" (wife?) is against having two good front speakers (wall mounted, bookshelf, even floorstanding) and a sub. With no long speaker wire runs, the front speakers can be wired pretty discreetly. IMO, this would sound much better for music than a Soundbar, and movies won't sound half bad either. Surrounds do enhance movie viewing, but if I had to have either a subwoofer OR surrounds (or course I'd rather have both if I could), I'd choose the sub. If you start off with two good speakers and a sub, you might be surprised how good it sounds. It also gives you a good foundation to build on if "the boss" decides to relax some of the restrictions
. Just my 2 cents. Hope things can work out well for you! Best of luck.