Given the plan is to keep the International League and Pacific Coast League without adding a third league to the AAA level, as well as the desire for Miami to promote Jacksonville to the AAA level, something has to give with balance.
Option #1: One of the IL teams moves to the PCL.
Either Louisville or Indianapolis ends up moving to the PCL, keeping both leagues at their traditional numbers. Louisville is the only team in the International League that is on the Central Time Zone, and is close to Nashville and Memphis. Meanwhile, Indianapolis would easily make a division with Omaha, Iowa, and the debuting St. Paul Saints. This would suck for the Indians, who would incur larger travel costs, as opposed to their current situation where they have one of the smallest divisions in minor league baseball in terms of travel, but as a whole, this would be the easiest option.
Option #2: The IL becomes a 20-team league
Moving Nashville, Memphis, Omaha, Iowa, and St. Paul to the IL would cause a massive imbalance between the two leagues, and cause scheduling issues in the International League, forcing teams in what would most likely be the Northwest Division to rarely, if ever, play against teams in the Southeast or Northeast (assuming that's how they would be named), but would easily solve the PCL's travel issues as one division would have OKC, Sugar Land, Round Rock, El Paso, and Albuquerque, while the other would consist of Salt Lake, Sacramento, Tacoma, Las Vegas, and Reno.