a single mega conference? Single network, multiple networks, simultaneous streaming, staggered starts, etc.
Let's say a conference expands to 20+, are we to believe that viewership is isolated for each school? If so, you could broadcast games simultaneously. If not and you want to maximize your viewership, then you'll stagger these games resulting in taking up an entire day or multiple days.
I'm certain there are many more ways to approach this challenge like limiting mainstream broadcasts to premier games with the expectation that your ratings will be very large for the few premier games. I just see this as a challenge for such a large conference to have multiple time zones where USC could be playing Rutgers at 8 AM PST or Ohio State at USC 10 PM CST.