Some ideas here:
(1) Plan carefully when you are going to migrate to each ODFB data so you can deal with throttling situations and also take into account the volume of data to be migrated
(2) Create a communication Plan to inform your users about the migration following a T-X, T and T+1 approach
(3) Start the migration on the agreed dates and migration windows and aftear each migration, review how everything has gone and solve any issues, problems found
Of course, I assume you will use a migration tool for that migration
