Just to clarify, you can use your FCC on any cruise not already fully paid. We've spoken to our TA and are able to apply it to our already booked 2024 cruise. This has been discussed several times above, so that is one less thing to worry about.
Am I happy about having 9 sea days out of 16? No, not at all. But I don't want our trip marred by lots of negativity and complaining about it. My husband and I are planning to make the best of a situation which is not what we originally chose and paid for, but here it is.