Signal does best with a clear line of sight between the AP and the client device, so it's more about obstacles than distance. This also depends heavily on what kind of antenna you have attached, and what the power level is for the AP. Environmental factors will have an impact on this as well, specifically metal, glass, water, or large amounts of people. All of these factors will absorb or fragment the signal, and with a football stadium we have at least two of these factors in large quantities. Something else to keep in mind is that each of the AP1130's radios can hold 100 clients at best, so you'd be able to have a maximum of 200 clients on the AP.
For best results you'd want a few APs within the football stadium, preferably mounted away from any metal or glass if that's possible, with a clear line of sight between the AP and the wireless client devices.
