We did have some notable blocking in late Nov 2017 and mid-Nov 2018. Issues were Nov 2017 was a dry northerly for Ireland and the air wasn't that cold.
The continent was too mild in Nov 2018 to produce anything notably cold or any snow but the cooler air from the east did produce heavy rain in southern and eastern counties as it contrasted with the mild Irish Sea. A Scandi High (not a -NAO though) did reappear in mid-December but continent not that cold again and Ireland on the periphery too.
Nothing unusual to be seeing cold and settled weather in November during a La Niña year. That GFS 12z operational run was the holy grail pretty much and its verification would be extremely low regardless of the timeframe it was projected at in FI because it is such an unusual pattern. As to be expected, the latest 06z is gone completely the other way with a mild southerly. It's called Fantasy Island for a reason.. though I would not be one bit surprised if we did see another mild southerly at some point.
At this moment in time, I doubt there will be any snow conducive synoptics and cold from mid-November and the most we will have is cold and settled with frost overnight whilst sunny or foggy by day akin to late November 2016 due to high pressure over or close by.