Well, this year is a little bit different.
IOA closes at 5pm.
USF closes at 6pm.
Happy hour ends at those times.
After that, you're drinking beers at $5 a pop. They also have tons of bars set up around the park which are walk up stands. They have red lights flashing above them. I never went up to one of those, but had a $5 beer before the event started.
The big trick is to be in USF around 5pm, have a few drinks at a bar like Finnegan's across from the Mummy, then head to the stay and scream area (next to Neutron) to do the 2 houses before the crowd is let in.
As you exit these houses, you can buy another beer from a stand while you wait for the go at 06:50pm.
After that, you can buy a beer, or a drink from the bars in the park and that will keep you going. Plus they have girls selling jello shots in the lines.