Hi again Jenni!
The cruise I mentioned booking for January 2026 is actually a B2B (back-to-back) combination of two cruises, both R/T (round-trip) out of FLL (Fort Lauderdale) on HAL. I think HAL will be a good fit for you by the criteria you mentioned.
Our cruise is comprised of a 12-day cruise plus a 9-day 'leg', first is partial transit of Panama Canal, second visits the ABC islands (Aruba, Bonaire, Curacao) AKA "southern Caribbean". Those destinations may not be what you are thinking of for a Caribbean cruise, but I would suggest you do look for something at least 7-days and preferably longer, and not during Spring Break times. The shorter later spring cruises sometimes attract a party-crowd, commonly called Booze Cruises.