Great vacation place in month of december ?

Was planning on taking a vacation during the christmas holidays this year . Would only have a week . I live in houston and my family includes me , my husband and my toddler son .

Please suggest some nice vacation spots that can be enjoyed in just 5 days .

Also , since we have already been to San Francisco and San diego . Please rule these palces out .
tahnks for th ereponses . i am looking at some place not too cold for my son .