Are there AA routes MIA-Carribean to islands far enough south for beach weather?

If you're willing to take long flights, northern Australia would be good for the weather but check that it's swimming season in terms of the irakongi (spelling?). Cairns and the Great Barrier Reef, Sunshine Coast, and Gold Coast are the areas I'm thinking of, but you could also go to Darwin or the coast north of Perth. QF is in oneworld although IFC award availability might not be easy for two.