They really are incredible ensembles!
Can I just say I don't post in here very often at all as I'm what is (probably) known as one of these Netweather 'lurkers'
I took one look at this forum tonight after the ECM 12z tonight and thought the end is nigh...and this cold spell might be odds off, gone in the tipper and burnt by the Atlantic. But actually, you look at the fact that the ECM 12z op is a really big outlier - this really just shows how strong the signal is for the block to set up in this way. The GFS 18z is just outrageous and is (in my honest opinion) an extreme solution.
It seems to me, though, all models have got this block sorted and pretty much nailed. The only question is...just exactly HOW much snow??