I've just had to cancel our Christmas Day dinner in a local restaurant ~ booked September 2019! We've just gone into Tier Two and the friend and I who were going are not a household or a family or a bubble. Of course we could change Tier for the better by Christmas (cough) but we thought it kinder to the restaurateur to let him have the table back to re-sell sooner rather than later.
I've had people say to me, "Pretend you're a bubble for the day" but NO. If it was "Pretend you're a bubble for the day and sod the Luftwaffe", then I probably would but "Pretend you're a bubble for the day and potentially risk giving and/or receiving the virus for Christmas", then I definitely won't.
Plus, as I've been 100% compliant so far (consciously, anyway), and have had plenty to say about those who consciously have not, I lack the hypocrisy required!