We’ve been lucky to be offered move over deals twice, both pre Covid.
First was a cruise from Adelaide to Singapore, where we gave up our balcony cabin for an inside cabin of our choice on the same voyage, in return for a refund of our cruise fare as refundable OBC and specialty dining.
Second time was Sydney to NZ return, where we had to give up that particular cruise completely and choose another in return for our cruise fare as refundable OBC and an upgrade from a standard balcony to a deluxe aft balcony.
We elected to take up both offers as they worked for us and thanks to the advice from fellow CCers, I knew to get right back to them and grab them straight away!