Broadly, I'm seeing good potential for some negative NAO days in December (perhaps late Nov too) with associated cold UK weather possibilities, after which time it will come down to how much the polar vortex is interfered with or able to flex its muscles.
Whether a sudden stratospheric warming (SSW) occurs is of little consequence until late Dec, IMO. Rarely is the polar vortex coupled enough with the tropospheric circulation before then for it to drive a persistently zonal regime otherwise.
Recent years have seen many incursions from the north or northwest in Dec. Trouble is, as others has noted, the air from those directions, in early winter, doesn't tend to be cold enough these days for widespread settling snow at low levels.
This year, the La Nina and negative Pacific Decadal Oscillation (PDO) combination should encourage some more pronounced northerlies in terms of fetch and duration. Whether that will be enough to overcome the handicap of climate warming, from the perspective of those seeking snow cover at low elevations, we can only wait and see!
By Feb it could become very mild if the polar vortex is strong.