Here's what you need to know, I tailgated there for 15 years, and have since moved to the RV lot. First, you don't have to have a Lot 100 pass (Lot E for football) to tailgate there. It is open for anyone to tailgate there.
You will need to get out there on Thursday around 10:00 PM and prepare to stay there all night until they blow the horn on Friday at noon. During that time, walk around and talk to all the "legacy" tailgates about where you can fit in. You want to know exactly where your stakes are going before the horn sounds, and that only happens with communication. When the horn sounds, for as big a game as this is, you will still have people try to beat you to your spot, so be stationed on the sidewalk closest to your spot. As new people show up through the night or early Friday communicate right away where "your" spot is going to be. It will NOT be easy to find a large area to claim anywhere at Reed.
If I could make a suggestion, right across the street is lot J (lot 97 during school) and there is a good amount of green space next to the Borlaug Building. For a group your size that's where I'd be looking to setup. You won't have to get out there Thursday, you'll just be able to show up around 11:00 AM on Friday and you'll be able to stake out as much area as you need (within reason). The walk is practically the same from the tailgate to Kyle, you can still park in E and walk over. You'll still feel like you are "in the mix".