Nup. BA used to fly LGW-KEF but this stopped a few years ago - sadly.

You might have more luck with the Northern Lights from Alaska - such as FAI. Far colder in winter than KEF but may be more rewarding. That said, the only times I have seen the Northern Lights have been from midnight flights northbound to ANC about an hour short of ANC.

Its a miserable experience driving around looking for a dark place on the outskirts of FAI in -26 degrees waiting for the sky to light up.