❓ When using an S3 bucket for remote state, is it possible to move that remote state to a different S3 bucket / path, or does it need to be torn down and recreated in the new location?

With care, you can move it. You can update the

backend

property in your project YAML and manually copy the object tree at the same time.

Cool, that’s what I suspected. The backend state path isn’t anywhere except in the Pulumi.yaml file?

There's a default value for it stored in a config file in ~/.pulumi somewhere, but that's only used (afaik) when creating new projects.