Maybe change the SSID/Password on the router in either the Shop, or House, so that they are different and then just ensure whichever WiFi network you do not want the Sonos product to connect to is not stored in the ‘Settings/System/Network/Manage Networks’ area of the Sonos App. If the ‘SSID’ is not listed in the settings, it won’t be able to connect to it… and …
Just to add there are other ways to resolve your issue, just as a further example, if you wish the wireless networks to have the same SSID/Password instead, then you can likely stop the, Sonos One connecting to either router, by simply using the routers ‘MAC address filtering’ options in the routers configuration pages… most routers have that option normally, so check your user manual.
There are undoubtedly other options, but those are the first two simple ones that spring to mind.