I got in line last night just after the first show had let out, and I made it into the 6:45 show, though I believe I was in the last group to be let in. I was going to try for the next show as well, but the standby line was just past where it was when I jumped in for the 645 show, and I didn't feel like risking being cut off.
The CM manning the line did say that the 6:45 show was the busiest in terms of dining packages, so I probably could have made it in again if I really wanted to.