When it comes to the US, which route would be most viable? ORD or JFK?
Neither. The airport management have been 'wined and dined' in Chicago last year in order to try and restart the route, but so far no takers. Why would any carrier want to restart JFK again, when EWR is working well? Remember the on/off LGW-JFK back in the 80's/90's? BA restarted that route and stopped it when it didn't work.