Had the house to myself yesterday so I tried a couple of the suggestions mentioned here. I covered the TV and moved the table out of the room.
I can't say I noticed much difference in soundstage depth, but there was a noticable improvement in image focus. Covering the TV seemed to have the most effect. Moving the table didn't change things much, perhaps because of the books, plant, etc. that normally sits on it break up any reflections.
I'll see if I can come up with an inexpensive decor friendly solution.