Hi Countyline,
Your best bet is the use of point to point transmitters. Distance shouldn't be an issue with these types of devices but you would want a clear line of sight (no buildings or walls obstructing the transmission path). The setup I have always used in the past for these situations is to have the cameras, small POE switch (4 port), one of the P2P transmitters, outdoor housing and power provided at the pole. The cameras can run back to the switch at the pole which will be networked through the Point to point transmitter. All this will be housed at the pole in a lockable box and I would typically have an electrician provide a duplex inside the box for power pulled off the light pole. On the building side you mount the P2P receiver and run back to the network switch within the building.
The range extender would just create unstable networking conditions and you would more than likely experience quite a bit of packet loss.