Something tells me that the Big Ten is not done expanding. Below are the strongest eight candidates, as I see it. Only three of the eight have wrestling teams:
ND- 6th most valuable sports program, national brand
Georgia Tech, 47th most valuable sports program, 7th strongest tv market
Duke- 26th most valuable sports program, 22nd biggest tv market
UNC- 40th most valuable sports program, 22nd biggest tv market
Miami- 31st most valuable sports program, 18th biggest tv market
Colorado, 55th most valuable sports program, 17th strongest tv market
Utah, 56th most valuable sports program, 28th strongest tv market
ASU, 68th most valuable sports program, 43rd strongest tv market
ND will join any conference whenever it feels like doing so.
I could see Georgia Tech and Miami joining the Big Ten as a pair. Two big tv markets, plus good football recruiting areas. And together, they would extend the Big Ten's reach into the southeast.
I could also see Duke and UNC joining the Big Ten as a pair. Great academics and strong basketball programs in a decent-sized tv market.
I think Colorado, Utah, and ASU are long shots, but they would at least fill in the huge geographical gap between the Big Ten's west coast teams and Nebraska.