Looking at over NYE 2024 and when I tried to do a mock booking, these cruiselines don't show December: RCCL, NCL, Princess, Virgin, Celebrity, Holland America, Disney......
There may be more but I stopped looking. The 2 I DID find are Costa and Viking. However, it sounds like the weather will be quite cold in the Mediterranean at the time of year so I think we will stick with the Caribbean over NYE.