One more variable: How many people are in your party!
We got into line a half hour early, and were standing way back past Morocco. And the narrator was Whoopie Goldberg! Seemed hopeless, right?
Well, about 15 people joined the couple standing ahead of us when the line started to move. A woman with a baby carriage was being especially obnoxious about not splitting up (which I found hilarious, considering how far back we were).
When we got to the stadium, it was looking pretty full. My husband I passed the group of 17 who were milling around looking lost and headed to the far side... and then down the aisle, where we found fantastic seats for the two of us. We had a perfect view - not too close (we made that mistake one year!), and nothing blocking our view.
The group of 17, by the way, did manage to stick together, more or less. But they were stuck way at the back behind the trees. (
Why Disney has trees in the middle of a theatre is another question altogether!

)
Ones and twos can almost always find good seats, no matter how late you line up. Larger groups will have problems.