Extend/resurface rwy 05/23 at Newquay's other licensed aerodrome, install some lights and a nav aid or few, construct a modestly sized terminal and car park
Extend from 3.000 ft ? Given that the days of puddle-jumpers are over, you would need to bulldoze quite a bit of the surroundings to have a runway that could accommodate aircraft that are used for the kind of services we are talking about.
Probably in the long term the only way forward is a intermodal approach with much improved rail connections directly from a single airport gateway for the SW.