UNI 2007.
56,795 people.
45,800 actual seats.
By your "estimation", there could be no more than 3,000 people total on the hillsides. That would leave 8,000 folks who apparently either all hovered for 3 hours, or stood in the concourse area unable to see the game.
Or, just maybe, all 11,000 were actually on the hillsides.
No, its not possible-for comfort at least. If you ever look at the hillsides even the Iowa or Nebraska game they are not packed in at near the same density as regular seating. I think they just sell the tickets as hillside with the assumption that there is technically that much room there but people will not be able to sit that way-unless there is staff to order them to specific locations and they sit on each others laps or all standing-there are too many people on blankets and laying around and doing other stuff. I think there are capacity numbers at the game but a ton of them are always moving and walking around.
Look at it this way (sections 30-32) NE lower stands are the student sections and packed, Sections 30&31 I believe are 17-18 seats wide and 32 (half section is probably 8 or 9 seats), the total for the area is probably 2200 fans; 18+18+9 seats X 47 rows is plus or minus 2200 fans. If you look at the grass area to the adjacent to these sections (NE), it is never at near the same seating density because nobody sits in any order as they do in seats. If everyone stood closely on the grass hillside even at the bottom of the hill all the way to the north end you could get over 2500 people on it, but when has that ever happened.