Two crucial questions:
- The APs at the "remote" site is connected to the local controller, right?
- The Virtual AP connected to the controller is tunneled, and on VLAN 1 right?
Ok, so Whatever subnet that local controller is connected to, whatever the local controller considers VLAN1 is the ip addresses that the clients are going to get. Your controller can be another subnet where VLAN 1 is 192.168.50.x and that is what subnet the clients will be placed into. The VLAN a client is placed on is from the perspective of the local controller that the AP is connected., even though the Virtual AP VLAN is global.