Hi there, Deez72. Thanks for posting. There is currently no way to turn off or disable Sonos speakers, outside of unplugging them from power. You will also need to dig around your TV's audio settings to re-enable the TV speakers afterwards.
In the meantime, I am happy to forward this topic along to the team for consideration and visibility. Thanks again for the feedback!
Building community is like building a garden. You build the frame, till the ground, plant the seeds, feed the plants & sometimes you gotta pull the weeds.