Yes, you could set up the Sonos sound bar (Ray, Beam, or Arc, depending on size, connection type and pocketbook) and connect it to your TV. When streaming music, you would group the two ‘rooms’ in the Sonos software, and get the music out of both speakers. You can set up the TV input to stop the grouping, and then you would get the TV out of just the sound bar. 

Unfortunately, your Play:5 Gen1 rules out any new Sonos soundbar (Ray, Arc, Beam Gen2) as they are only compatible with the S2 app and your Play:5 is only compatible with the S1 app.

A second-hand or refurbished Beam Gen1 or Playbar would be options for you to continue using all the devices together on S1.

If you did only use the soundbar for television, your existing Play:5 should give you a 30% upgrade credit that you could use towards a new Sonos soundbar. Log in to your Sonos account online and check under System/Upgrade tabs for eligibility.

If you only connect the soundbar to the television (without surrounds or any grouped speakers) then only the soundbar will output the tv audio.

Ah, @Mr. T brings up an excellent point. If you’re running S1, my suggestion is moot. If you’re running S2, my suggestion works. 

Since I want to use my existing speakers along with a sound bar it looks like I will need to go with your recommendation of “A second-hand or refurbished Beam Gen1 or Playbar”.

I see some websites that are listing prices not in USD.  I’m in the USA…. best place/website to purchase?

Sonos offers refurbished BEAM Gen 1. Here is the S1/S2 compatibility list. Only your PLAY:5 is limited to S1.

You could upgrade the PLAY:5, then sell it. The new owner will not be able to use the unit for an upgrade credit.