Sonos makes a garden subwoofer? Can you please provide a link?

Aha! Not Sonos speakers, Sonance speakers. I finally found them after several minutes of googling at https://www.sonance.com/outdoor/garden-series

You may want to ask the folks at Sonance, but I wouldn’t think it would sound great, since it is designed to be partially buried, but you could certainly test at least half of that, and see if you like the sound.