So is it a pretty sure thing that there'll be open "film rooms" and such that we'll be able to sleep in? If so I'm gonna goa ahead and book the car and DC tickets
Are there film rooms running all night? At least some nights. Could you sleep in them without getting kicked out? I have no idea. I wouldn't suggest counting on that as a primary strategy. Security at Dragon*Con is an amorphous mix of con volunteers, hotel security, and Atlanta police, and they're bigger bastards about some things than you can expect from other cons. That's mostly because of the size of the event.
And...um...how can I put this delicately... If your plan is to wander the con for four days without access to a shower, you're probably not going to make a lot of lasting friends. I say this because there
are fans who go without basic hygiene every year, and you can usually smell them from halfway down the hall.