Obviously this doesn't factor in divisions or a twelfth team, but those two factors cannot be ignored. For example, we would more than likely be in the same division as Ohio State to prevent The Game from happening twice. That creates a massive shift in the power of the conference and the way these things shake out. Let's use the most commonly thought up divisional alignment and say, Syracuse because they would have been a non factor during this period:
EAST: Michigan, Michigan State, Ohio State, Penn State, Indiana, Syracuse
WEST: Illinois, Wisconsin, Minnesota, Northwestern, Iowa, Purdue
In this example, Penn State has a rematch with Iowa in the 2008 title game. If Iowa again pulls the upset, they go to the Rose Bowl and Penn State is a definite maybe for an at-large bid. Ohio State is in either the Citrus or Outback Bowl. If Penn State avenges the loss, they go to the Rose Bowl and Iowa heads to the Citrus Bowl. In this situation, 10-2 Ohio State is still in the picture for an at large bid to the BCS and likely gets it.
In 2007, we get Ohio State and Illinois. If Illinois repeats, they go to the Rose Bowl and Ohio State likely gets an at large bid and we still go to the Citrus Bowl. If Ohio State wins, they still qualify for the title game but Illinois is likely knocked out of BCS contention and takes our place at the Citrus while we head to the Outback.
In 2006, Ohio State plays Wisconsin. If the Buckeyes win, everything remains as it was... they go to the title game, we go to the Rose and Wisconsin heads to the Citrus. If the Badgers win, they go to the Rose and Ohio State gets an at large bid. Meanwhile, we're still ranked high enough to be in the BCS, but we're forced into the Citrus because there are already two teams ahead of us.
As to your later points... it's a gross simplification to say something like "Only option is Chicago coming back lolol"... there is a commonly held shortlist for Big Ten expansion (Missouri, Pitt, Syracuse, Notre Dame and, less frequently these days, Rutgers) that have been discussed at length. Rename the conference? Why? The Atlantic 10 has 15 members and nobody ever mentions it. The fact is Big Ten expansion is going to come within the next decade and we might as well accept it and have fun speculating who it will be. When Delany steps down, one of the first moves the conference will make is an exploration into a title game and expansion.