Backing up virtual Domain Controller using disk imaging

We have multiple Hyper-V Windows Server 2008 domain controllers located in one building.
I am trying to plan for disaster recovery of Active Directory in the event that we lost that site, and all the machines were destroyed.

Would the following plan work?

Prior to the disaster, we protect one of virtual domain controllers with Data Protection Manager 2010, using the Hyper-V “Backup Using Child Partition Snapshot” method, to tape. The tape is taken off site. We do not install the DPM agent on the virtual domain controller itself and do not take a backup of the domain controller’s system state.

The disaster happens, and all the servers are destroyed. We recover the tape from off site storage, and using DPM, restore the one virtual domain controller to a new Hyper –V host. No other domain controllers from the old site are restored. Metadata relating to the other domain controllers is deleted from the restored domain controller. We later add new servers, and join them to the domain, and promote them to domain controllers.

Because there we restored only one domain controller from the old site, then the problems with USN rollbacks and DFSR replication described in the links below do not arise, and the plan is good.

http://blogs.technet.com/b/askds/archive/2011/04/21/disk-image-backups-and-multi-master-databases-or-how-to-avoid-early-retirement.aspx?wa=wsignin1.0
http://support.microsoft.com/kb/875495
http://support.microsoft.com/kb/2517913

Is that right?

Thanks very much for your help
Russell