Boot from specified partition (or FS) UUID without knowing Device ID

I want to have a fallback boot situation where boot is first tried from one partition, and then from another partition (on a different device) if the first partition isn't available (eg, if the first device fails).

Can I boot from a specific FS UUID or a partition UUID without knowing a particular device ID? (I'm not sure if my devices will always be detected in a repeatable order).

Can fatload be used with only a partition UUID? Or can I somehow get the dev number from the UUID?

Thanks in advance,

Tom