When I was a DBA in Samsung Pay, I sketched a simple database migration plan above. We wanted to move the existing data center to another. At the early phase, we didn't use a cloud infrastructure because most of us thought the cloud was not stable at that time. So the above plan would be now kind of a old-fashioned one.
I cloned and isolated the test group from the production which made the production group is not affected by the test. Then I used the filename and offset to catch up the production binary logs as the last step.