When my wife and I did the Keys to the Kingdom Tour quite a few years back, we were the first tour of the day. That gets you in to the park before anyone else *or at least it did when we did it. Your tour starts down Main Street, and then the guide brings you to the side and your tour group stops to listen to the opening show, and you get to stand there in a group and watch everyone else stream into the park.
I will tell you this: It was AMAZING to experience it that way. Think about how many hundreds of millions of people have been through there, and then think about at that one moment, YOU are one of the first small handful of people in the park. It most definitely gives you a unique feeling. Now ... you don't get to take cameras on that tour, so you can forget about documenting the experience.
I'd check the times, though, to make sure that tour still starts you early enough to make that happen. (And by the way, that whole tour is outstanding, as well, and you get to go backstage as well as in the utilidor tunnels under the park.)