Been watching the Railcam.uk streams on YouTube. Doesn't look like a lot of snow to me ... maybe three inches at most.
https://www.youtube.com/watch?v=F_HMyfBPuAs" onclick="window.open(this.href);return false;
The above link is for a camera at Barking which I assume is near London.
It seems to me, looking at the video linked below, that BR had less problems with snow in the past -
https://www.youtube.com/watch?v=cl4pJwcE7JI" onclick="window.open(this.href);return false;
Snow (1963) - Geoffrey Jones | BFI National Archive
My favorite parts of this film is at 1:17 with the signal box operator throwing a switch while a coal fired fireplace in the background and a steam train blasting through a snow drift at 2:05 .... can't do that with a 66 I guess ....
BTW - if it helps any, the Amtrak NEC was completely shut down between Washington and Boston yesterday due to a "nor'easter" blizzard which caused trees to blow into the catenary.