I realize that there are children who will eat themselves sick. My guess is that they won't do it more than once so why not let them get it over with? The children who will eat their entire bag of candy in two days regardless of consequence? Take them to less houses. I think the whole approach of "restricting" leads to anxiety but that's just me.
Anyway....Have a safe and happy Halloween!! And, don't forget to eat LOTS of candy:)