First, you don't want to be in DCA during the Halloween party. You want to stay in DL since you paid good money to go to that party. You can do DCA before the official party time if you want. This is the first year you can go to DCA before the party with a party ticket, so it remains to be seen how crowded DCA will be. But as far as the party goes, you don't really need a ride strategy. Lines are pretty non existant. Of course they get shorter as the night goes on, but with the exception of the most popular rides, everything else is almost a walk on. Even the popular rides have pretty short lines.