I've been wondering about this too. The trend for blockbusters in these parts recently has been a sneak 7:00 pm showing before the proper midnight opening (this is how I saw Jurassic World). That would be ideal for me, but I'm not sure if Lucasfilm can block that, or even if they would want to. In any case, it's been years since I actually needed to get tickets for an opening more than a few hours in advance (I think the last time was The Dark Knight back in '08), but I don't want to take any chances with this one. Not a very helpful post, I guess, but I'm curious too.