My best bet would probably to add a base at Bournemouth, as this is the base I believe of parent company Channel Express and also beside the Dublin and Girona flights by Ryanair, it is one of the few remaining airports in the South West without a significant low fares airline presence.
Out of Leeds-Bradford, I would presume the airline might try to add one or two new business cities, perhaps Paris and Frankfurt with two flights a day and one or two more leisure cities with one flight a day like Naples, Madrid or Mahon.