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Is UC Davis ready to assume the additional risk for tier-1 services or would it make more sense to first move tier-2 and tier-3 services offsite?
Virtulization
As more services are virtualized on campus it would make the transition to a remote location more seamless. The virtual images of the servers could be transferred to a remote virtualization service with minimal downtime and without the need to move physical hardware.
Recommendation
In short, there are no technical issues with co-locating services remotely as long as the service owners are aware of the risks and work to mitigate them where possible.
Once the infrastructure for remote hosting is available, as new services are brought online hardware could be purchased and shipped directly to the remote location. Overtime the proportion of services at the remote location would grow while locally hosted services would shrink.