Beautiful, beachy, relaxing honeymoon in late October?

My fiancé and I are getting married October 17 and are trying to decide on where to honeymoon after.

We’re looking for a place that will be warm and beautiful, temperatures in the 70s or 80s F, perfect for bathing suits and beach – with maybe a few days of cool sightseeing.

We know we want to travel outside of the United States. So far we’ve shown the most interest in Greece and Portugal/Spain, but are worried that late October isn’t the best time for a relaxing beach trip to those countries.

Any help and suggestions are really appreciated!