My last long haul was on Dec 16th this year, nothing particularly Christmassy going on then either in the PFD at EWR, onboard, or at GF (although it was early).
I took a couple of short hauls last week, by this time there were mince pies in GF and some mulled wine on a little trolley by the entrance. It appeared some time after about 1pm.
Perhaps it's been a while since I last lived in the UK, but is there something particularly Christmassy about pickled herring? 22nd Dec CE leg, fish salad inc. pickled herring. 23rd Dec, the GF Chicken Caesar Salad (or as I prefer to call it, Caesar Salad with a chicken leg dumped on top) came with pickled herring on it, then the CE leg on the 23rd there was a slither of pickled herring on the salad frisee that accompanies afternoon tea.