I think that the smaller places get less spring breakers. The farther from a big(ish) airport the less chance of spring breakers. You will always have local spring breakers.

So look starting at Sarasota, Longboat Key and heading south to Naples. If you can fly out of Miami then it would be just as close as MCO. Or you could look at RSW but would have to make a change.

If you want to know if the local public schools are out that week you just need to know what county. Then you can find the website for that school district. There will be an academic calendar that shows when the kids get days off. Might be handy to know.