Got to the train station this morning to find it all snowed in. Eventually a train turned up (30 mins late) but was so full no one else could get on. They then started canceling other services. So, I went home and dialed in to the office for the day instead. Turns out to be a good choice - we've had much more snow since and it looks like all trains might be canceled coming back out of London! Here's a pic from my front door webcam.