Take it from a former cast member, the rule of thumb for Disney trips, if you are trying to avoid the crowds is "if anyone is out of school anywhere in the country for any reason it WILL be busy". There are hardly any exceptions to that rule. If any district is out for spring break, summer break, fall recess, winter break, weekends (especially 3 day weekends), and most holidays. It WILL be busy. It doesn't matter that your son's break is a little later than most, because it still means kids are out. Busy busy busy!