Indeed,there will still be a lot of uncertainty even on the day of the event in this situation.Going back to the seventies and eighties when this type of event was more common, a straight on south west attack was often repelled if the block was strong enough, what eventually broke it down was an undercut slowing down over France and sucking up some milder air from southern europe, this was mixed in as a south easterly, cutting off the supply of cold air from the east and opening the way for a conventional Atlantic push.
Whether that will happen here is anyone's guess!
I think your comment yesterday about some people getting a snowy plastering, some getting rain,and some getting nothing, is spot on.