There are plenty of airports which could sustain a Ryanair base: Teesside or Doncaster / Edinburgh / Aberdeen / Treviso / Forli / Trapani / Wroclaw / Oslo Torp / Reus / Marrakech? / Beauvais / Salzburg / Bratislava / Novi Sad
Would love to see an evening frequency out of Luton to Rome. A reintroduction of Treviso would be good.