Well Delia's Lounge will let you have a private party for $40 a head. It includes food, and im pretty sure it include drinks also. If you want some info on delias go here: BayRidgeNights review of Delia's Lounge.
I know some what how you feel. My office is open 365 days a year. They're usually pretty good about letting people take off when requested. But there is always a looming fear that you'll get that call saying "come in"