ZOS,
For the next round of campaigns, why not scale down the # of Cyrodiil instances until population demands it?
Virtualization and automation these days can be setup to handle this. Why not start with 2-3 campaigns, and when thresholds for population in these campaigns reach X (whatever number is deemed suitable - say 75% full) - have another instance spun up?
This could help to resolve population issues.
Also, to prevent one faction waiting around for a new instance if that faction is full - introduce population auto-balancing.
Thoughts?