Need recs of products for clinic

I’m currently helping an owner of a small clinic find speakers that work offline. He had tried sonos speakers previously but it was too difficult and inconsistent with updates messing up permissions and locally stored playlists.
The main thing is we’re looking for recommendations of products from acrylic to achieve a setup where there is 1 speaker in about 5 rooms, without wires running to each. He wants this done without the use of wifi in case of wifi outages he could still play music from a laptop. No limit on budget.

Without a wired or wifi connection the only option would be Bluetooth but this has range limitations indoors especially though walls although this might be achieved or overcome with repeaters.
Personally I would ask them to rethink using a wifi connection as I think it would be the better wireless choice in this situation.
Am I correct in assuming the same source content will be sent to all of the speakers?

Yes, the same source content will be sent to all the speakers.
The biggest reason he’s looking for an alternative is because of sonos software issues or if wifi goes out, just something consistent enough that doesn’t require software updates that may screw things up.