If we're playing Mr. Potato-head with these conferences, here's how I'd align them today if there were no existing conferences to deal with.
Penn, Elkhart, Mishawaka, Warsaw, Carroll, Homestead, Snider, Concord
Jimtown, Northwood, Northridge, Plymouth, John Glenn, Goshen, Wawasee, Bremen
Riley, Washington, Adams, Marian, St. Joe, New Prairie, Clay(until they're closed)
This would house all the NIC and NLC teams in a better arrangement than they're currently in with probably the exceptions of Marian and St. Joe. Also I'm not sure if this is better for Carroll and Homestead than the Summit but it does cut down the Summit to a more manageable 8 teams.
Anyway you slice it, it looks like trying to solve the Penn/NIC problem creates more problems elsewhere. Probably the best solution is just to let them go independent.