Actually I was thinking that the easiest re-use of that one slot pair is it adding MDW-LGA. It'd be a lot easier for Frontier to market New York City as a destination to it's Chicago Frontier flyers, than Orlando or St. Augustine to the smaller group of NY area based Frontier flyers since F9 is so small in the NYC market. It's also shorter by a couple hundred miles than LGA-MCO.

Frontier is slowly getting off the 3rd party booking sites as well. It'd have a tougher sell competing against JetBlue and Delta without much awareness.

A Frontier MDW-LGA at 1x daily, would just be like Spirit increasing it's 2x daily LGA-ORD to 3x daily in the overall NYC-Chicago air market, which is huge.