Please don't let your inner Scrooge out of the closet for this question.

It seems miles away yet, but I've just booked my flight home for Christmas before it gets outrageous. BA, shockingly, came out priced best for a return from BRU to MAN on Christmas Eve and back in January when taking into account luggage. My flight gets to MAN around 18.15. Getting it fine to get into a festive mood, but what can you do? My last exam is around 18.00 on the 23rd.

However. It's Heathrow. It's winter. The omens are not good. If my domestic flight is cancelled, and they tell me I have to travel on the 25th, may I politely decline and travel on the train home to get there before Christmas Day without invalidating my return flight?