Exchange Database & Log Files can be stored off the server using Windows Storage Server.
This off-server storage can be part off as DFS
This DFS storage can be replicated to another location via Windows
Can you therefore replicate it to another exchange server (local disk) with services disabled as a quick DR solution?
Should you need it just rename the server to match the now downed server (as it must be different from the running one) and start the services (as DB and logs are present)
??