> Even if you have a DR plan you should assume your incremental backups are no good and you need to restore the whole thing from scratch.

"Restore from scratch" can mean a lot of different things, if you have a read replica that you can promote then in relative terms to 72h+ downtime, this should be fairly quick, no?

If you have block-level backups or snapshots, with ZFS for example as someone mentioned, it should also be relatively quick -- although I assume this would make any hypothetical read replica split-brain.