Thank you for the answers and the insight! I am hopeful that they can work it out since, as you point out, it's possible to buy a drink package individually. I suppose at the worst, if they can't get it fixed on board, they would just refund the entire package. That would their financial loss, because at that point I likely wouldn't spend nearly what the package cost.
Our cabins are actually not exactly on the same reservation. We have 4 cabins altogether - separate booking numbers but they are all linked as "traveling with" or somesuch. I am not sure. I paid the deposit for all 4 cabins, but they definitely have separate booking numbers.