On 18 Dec, 14:19, Mizter T wrote:
So, I dispute your notion that there is no public transport on boxing
day!

Apart from coaches there isn't, from Cambridge anyway. If he has to
drive to London then why not spend the extra time going round the
m25.

Apart from the direct coach, you could drive her down into London
and drop her off at a Tube station for onward travel via the
Piccadilly line to Heathrow (max fare £4 with a paper ticket, less
with Oyster PAYG). The easiest Tube station to get to from the M11 is
Redbridge (Central line), just off the North Circular.

Epping is about 5 minutes from junction (7?), and allows you to get
off before you hit the m25

Debden is right next to the M11, but sadly you can only get on/off
going south.