It won’t sound as good as it would if perfectly placed but it should sound pretty decent.
How high is the ceiling there?
20 feet is a bit far too.
You’d see the same or worse from similar soundbars too. For odd rooms a multichannel (7, 9 or more) AVR is often the best solution, feed it with a Port to get your Sonos audio playing.
Thanks very much, Stanley_4. It’s a cathedral ceiling that peaks at 5feet above the shelf where the Arc would be.
Sounds like it is pushing the distance for the Atmos sound too, although being that high would be better than below the TV.
Have you considered some high quality but small bookshelf speakers and a Sonos Amp instead of the Arc? Maybe placed on the shelves beside the TV instead of high on that shelf? I’d really lean that direction myself given your room size, height and seating distances.