I have been told that the best wireless solution for IP cameras is point-to-point. I did a project where we specified point-to-point, but the owner had point-to-multi-point installed, and the inherent delays in that configuration caused severe issues with the iSCSI recording format. In spite of this, there are a lot of mesh topologies in use with IP camera systems. Just be careful of the shared bandwidth issue.
One possible solution for the scenario you described is to use cameras with on-board storage, thereby reducing your bandwidth needs.
We would always do PtP but the camera locations change constantly.
The edge storage wouldn't apply since the customer wants to monitor constantly so we might as well record centrally anyways.
One of the challenges of using regular wifi mesh to transmit video is the latency added by the protocol, to improve the chances of having a better performance you need to use both radios to transmit the mesh traffic, to do this it is better to use 5 GHz band to increase the bandwidth available.
Doing omnidirectional mesh (full mesh) is not the best choice because if you have interference in one channel you will need to reconfigure all the radios working on it but I understand that is your only option as the points to connect change a lot.
I recommend to review Firetide as their protocol will help to reduce the latency. The price of each radio is higher but it is a good solution for video surveillance with nomadic topology.