Thank you all for the input. Pine Island does sound nice, plus we could avoid the Tampa metro area and take some secondary highways. However, I have a feeling that we'll end up in the Clearwater area (maybe Honeymoon Island if I can be a little more convincing).

We're going to be 18 people in four cars (with kids ranging from 6 to 15), so I will suggest we high-tail it out there around 3pm to avoid rush hour and most beach traffic to allow the smaller kids to take afternoon naps before NYE festivities start later that night.