I didn't really have a problem with the distance, but it was the time I'd have to get up to be back at the airport in time for check in :\ I think the flights to Frankfurt from Prestwick are one every two days (it's either Frankfurt of Duesseldorf) and I really can't stretch to another day there. Not when I'm in Berlin for a week just before Christmas :S

There is no way I am getting up at five in the morning in the freezing cold, navigating a city I've never been to and using a language I'm not fluent in just to get to check in on time.