Sonos observes this discussion and the customer frustration and dissatisfaction and remains silent!

Sheer arrogance. 
Sonos has become a company with a CEO who has demonstrated zero understanding of customer loyalty or how quickly customers can damage a company - he would do will to acquaint himself with the story of the damage done to Qantas by its CEO Alan Joyce.
Joyce pocketed his massive salary and bonuses as he drove up profit and forced Qantas’  reputation into free fall before he was forced out by his board.
Qantas’ reputation remains in the gutter while the new CEO spends millions to undo the damage!

Ok. I THINK I found it.  I'm playing Pandora "station"  there are only a few options on the screen with the app open: rooms, pause, volume, like or dislike. 

But when I tapped the image of the song playing, a new screen gave more options, on of which was sleep timer .  I hope that helps.  I set mine for 30 minutes. We'll see if it shuts off.