They know. Hell
@JStanz51 even said on one of the podcasts that he knows where it is at but can't say. There is absolute 0 chance that it is on the intramural fields though. I think center drive with the lots and stadium in the background would be great but would enough people show up that early to make it look awesome?
Have you seen how many people show up at Oregon/Oregon St when they've hosted? And the CGD broadcast starts at 6a PDT. For a first time hosting school, I'm betting fans come out in absolute droves. (See College Basketball Gameday here in 2015)
Site lines/back drop/etc. - If you've seen CGD once, you should have an idea how tall the set is. Cheerleaders have to be on one anothers shoulders to "photobomb" the broadcast, and even then it's usually only from the shoulders up. People have to attach their signs on huge [makeshift] poles to be seen. They'll be bringing in a huge camera crane to get those flyover shots of the crowd. I'm not worried about not getting a good beauty shot behind the "talent".
My one worry is that CGD isn't just the main set. They have a "mini-field" set up for Rinaldi and Wojciechowski to introduce their feature packages. There's also a possibilty ESPN Radio comes in, and they have their own separate set. (Obviously not as big) That's my (slight) worry.