Home Security Camera that is easy to turn off
There are likely cameras that have such a feature. But a simple solution is:


Use wired cameras, not WiFi
Connect all the cameras to one network switch. If you are using PoE then you are likely to do that anyway, unless you have other PoE devices such as VOIP phones.
Turn the "camera network switch" off/on as needed.


If the cameras have no substantial memory of their own, then you could actually leave the network switch "on" but disconnect it from the rest of the network. That would avoid any power-cycle issues as the cameras would not lose power, while still preventing broadcast to a recorder (whether local or in the cloud).