The best way to have this working the way you wish is to hardwire each speaker to your network, which will require proper STP/RSTP and multicast settings. Having them on a specific VLAN (like your IoT VLAN), with a single device connected to that VLAN to control the Sonos speakers, would be your best bet to avoid connection issues and dropouts. I would not use them wirelessly for this deployment.
Ask your IT department for help with this. I am sure there are a few VLANS already created for different departments as well as things like servers.