It is possible with DCN to deploy any number of remote compute sites, each with its own Availability Zone (AZ). Once the site is provisioned, specifying the site's AZ when launching an instance is all that is required to launch an instance, for example:
openstack server create --flavor tiny --image cirros \
--network edge-management-vxlan \
--security-group edge-management \
--availability-zone AZ_DCN_2 \
edge_vm_1