Vasco nailed it I think. The destinations from Miami are south (Keys) and east (Bahamas). Heading north, you will find it is a long distance between inlets (Port Everglades, then
Lake Worth, then Ft Pierce, then St Augustine), and
anchoring out is difficult with prevailing easterlies (NE in the
winter, SE in the summer).
If you don't mind making the long jumps between inlets, then you'll find plenty of shelter in the
ICW unless there is a cold front.
Pete