I put this elsewhere in the thread, but you can also set up bi-directional S3 replication. I haven't used it in production, but in theory it would mean you can

I put this elsewhere in the thread, but you can also set up bi-directional S3 replication. I haven't used it in production, but in theory it would mean you can continue write operations during failure. And those writes that are committed to the primary but not replicated when the region goes down wouldn't be lost, they'd come back up once recovery is complete (S3's SLA for data integrity is a lot stricter than it's uptime). Whether or not that is acceptable depends a lot on your use case.