Do you have any idea if you want structure or non-structured?

I spend a lovely christmas on Grand Cayman once, mostly Scuba-diving, which provided a bunch of structure, in terms of schedules and such. I've also done trips where the only fixed points were my arrival and departure flights, not even a hotel arranged until I wandered into the city.

Southern Europe, or the Middle East could fit your warmth requirements, as would South America....