In message , at 23:29:48 on Wed, 2 Jul
2014, John Levine remarked:
NatEx have coaches from Cambridge to Luton Airport every two hours
from 02:20 to 20:20. They take about 1:35. Seems reasonably
accessible to me.

Ely is harder. The Cambridge train station is a long way from the
coach station, so it's not a very good place to change.

Indeed, I'd have to allow at least 3/4hr from home to the coach stops in
Cambridge.

The coach stops at the Hitchin train station, but you can't get there
from Ely without changing at Letchworth.

The xx.30 semi-fasts stop at Hitchin, but a change at Cambridge is
necessary because the Kings Cross trains from Kings Lynn are fast
Cambridge-KX.

Or you could take the train to Stansted airport and the coach from
there.

But it's an hour to Stansted Airport (more or less) so two and half
hours, plus the latency of the change at Stansted isn't very attractive.
--
Roland Perry