[codingdave]

The low likelihood / high impact edge case this does not handle is: "Oops, our data center blew up." An extreme scenario, but one that this method does not handle. It instead turns your most recent backup into a single point of failure because you cannot restore from other backups.

[datastack]

This sounds more like a downside of single site backups

[codingdave]

Totally. Which is exactly what your post outlines. You said it yourself: "Only one full copy is needed." You would need to update your logic to have a 2nd copy pushed offsite at some point if you wanted to resolve this edge case.