There will be a 70msec delay on audio-in via any line-in or Bluetooth input on a Sonos device. Line-in quality will be better than Bluetooth but the delay may make the solution unacceptable. 
 

You will only be able to play stereo from the tv; no home theatre 5.1 or other formats would be supported. 

Thanks for this info. I will have to live with this solution for awhile. Cheers  

Hi 

I don’t know your timetable to acquire the Arc Ultra however you might consider a soundbar in the link temporarily. The upside is that you won’t break the bank, and you'll not have the 75ms delay which will be a lip-sync issue. 

Amazon.com : tv sound bar

Don’t count on it as a “feature”, but some cable box video is so laggy that the 75ms audio latency is a benefit. And I’ve seen it the other way where audio already lags at the cable box exit.

I already have this issue with my Direct TV service. My wife complains about it but it doesn’t bother me at all. I just enjoy the ride.

If you use an AppleTV you could just select a stereo pair of the Era 100s as the Audio Output, until you purchase the Arc Ultra.

Unfortunately I don’t know an Apple TV. I have a 60” Sony Bravia dating back to 2014. Thanks for you response & suggestion.

AppleTV is an input device to a TV or conventional A/V system. In that respect it is similar to ROKU.

Gotcha….what do I know? I’ll look into that. Thanks