I'd do the 'ole bowl of candy on the porch, but I'm pretty sure someone would take to bowl.
Tell your roommates to leave it alone.
Actually, shutting everything down does not make you a bad person and not doing it at all is better than running out about halfway through the night. My neighborhood is not that hard to predict. Generally, about 75-100 kids and it runs from about 6 till 8 PM. Pretty consistent for the last 6 years.
Halloween was one of the few fond memories of childhood for me. We traveled in packs and had a runner take the bounty back to home base so we didn't have to pack it the whole night. Back then, it wasn't an issue for kids being out on their own without adult supervision either.