Best answer by AjTrek1
First there is no need to have a different Wi-Fi at each house. You could set the SSID and Password to be the same at both locations. Sonos or any other Wi-Fi device would not know the difference and automatically connect. There are no "flavors" between 2.4ghz at House A vs House B
What is happening now is your Sonos is looking for Wi-Fi credentials at each location. I suggest you do the following:
1. Set both locations with the same SSID and Password
2. For now go to your iOS or Android device tell it to forget the Wi-Fi from the other house
3. Connect your device to the current network
4. Following the instructions in the link to get your Play 1 back on the alternate network: https://support.sonos.com/s/article/1061?language=en_US
I hope this helps. Cheers!