There isn’t really any good way to do this.  Yes, you can setup Sonos speakers as a separate room, then use Sonos grouping function to play the TV audio in this separate room.  However, removing your Ones as surround speakers, setting them up as a new room, and trueplay tuning them each time...is not a 30 second job.

If you’re looking to get TV audio in a different room on a regular basis, I would strongly considering just buying another speaker or two.  

Thanks for the info - If I were to get an additional speaker, how would I set up the speaker to be used as a multi-room one with output from the TV?
(Alternatively, what is the process to set the 2xOne’s I have as being able to do this full time?)

Sonos supports a feature called Group. It allows the same source to be played to all devices in the group - so for example you can send the TV source to the new One’s in the second room. Note there will be a 70msec delay on the TV (only) signal to the other room(s) but unless you’re in a position where you can hear the Arc and the One at the same time and at about the same volume it shouldn’t matter. I use this feature a lot to listen to the tv program when I’m in the kitchen.

Thanks so much!

This has worked! For anyone who may view this topic looking for how-to..

First, unpair the surround set-up.
On the app, click the 4 vertical lines at the bottom…
On the options that appear, one will be the Arc, select the little square on the right.
Then add the other speakers (might be listed as rooms) to the that group.
All speakers should then output the TV.

Thanks for your help!

You got the answer for grouping already.  To remove the surrounds…

https://support.sonos.com/s/article/4803?language=en_US

After done, the removed speakers should automatically show as a new room.  You can then go to that rooms configuration to name it, trueplay tune it, etc.