I've done migrations of several databases with ~20TB of data before. Assuming you're data is immutable, A much easier approach than what they did is to restore a backup of the database onto a new machine. Since you don't have to worry about serving production traffic you can have the machine go full throttle on performing the migration. When the migration has finished you have to copy the new data that came in during the migration into the new database which isn't too bad.

When I've done this with 20TB DBs, it usually took several days to complete. That's much better than the 11 months mentioned in the blog post.