Sometimes when it is busy at opening, they will hand out tickets like a fast pass to WW (not any rides, just the land itself). In our case, I waited in line in Jurassic Park with my youngest and we got into WW about 10:30 (we arrived a little after 9). My oldest and my wife got the pass, which let them in around 10:50 (but of course they could walk around in the meantime).
There are threads about fitting on the ride. I have about a 52" waist right now, so I knew I would not fit. My wife is about a size 24 and she did not fit either.
It seems if your chest, gut or thighs are above average, it might be tight. They might get you in by pushing hard, which could make for an uncomfortable 5 minutes on the ride.
I have heard that those over 6'5" or so have issues too, because their legs could hit effects in the ride.
There are test chairs out front to see if you can make it.