It would be very cool to have decent web access from the stands and under. it's not that easy tho unless everyone has a unique password, it's all or nothing. Technically having an open-ish wi-fi and limit the bandwidth per user is fairly straight forward, just expensive for such large number people in one spot to have fair access, as far as I know.
I prefer company service provider's internet.because at that time not much traffic uses companies internet.So if you want to use internet, leave stadium's Wifi and go for yours internet. Hope that it would be more convenient that theirs.