Maybe IND? But at the end it's so hit or miss, I'd take the most convenient airport. To any of these you're almost certain to get a MCE seat (or maybe even a row in Y) and its such a short flight...it's not worth deviating for an elusive upgrade. I've personally declined upgrades on the E170 short hops when I can get an entire row to myself vs being assigned next to someone on the C/D side in J.