It looks like you're talking about sending a snapshot of your local exchange server to AWS?
That's not likely to work terribly well, Exchange's system works around transactional databases that need to keep their integrity in order to function properly, and snapshotting is likely to mess with that. Also, I suspect you'd lose email while stuff was "in flight".
To make this work reliably, you'd want a "local" DC in your AWS virtual server farm, or the AWS service Tim suggests, and it would still be a bodge. You'd be better off working with the High Availabilty options built into Exchange itself, such as Database Availability Groups (DAG). Microsoft have some good documentation on how this might work here.
Keep in mind that you're also going to need to think about updating DNS to deliver email to the right server in your scenario (you can't have multiple MX records existing in your scenario or you'll lose email when a temporary 'blip' in your main system's availability causes messages to go the second MX entry). This isn't an "instant switch over" option if something goes down in the middle of the night, and also DNS TTL will be a factor.
If you really need your Exchange email to be highly available and you're obviously not against using cloud services to achieve that, I would suggest the best option of all would be to use Office 365 and Azure Active Directory. I've got several thousand mailboxes in O365 and I just don't worry about Exchange availability any more because Microsoft do a great job.