i know that around closing Casey's Corner will close aprox 20mins before official park close.
i think if you headed there about 30mins before park closing you could grab food and i dont believe they would kick you out when its park closing time, i know most of the shops will remain open for a short while after park close because they can make money! so i would grab yourself a caseys corner 30min prior to closing to be sure then slowly eat that and have a casual walk out down main street
dont forget if your staying until park close you can also catch the ''Goodnight Kiss'' thats usually around 20-30 mins before park closing i believe! its one of those little hidden gems that isnt listed in the park times guide