Red is where some light icing may occur predawn Wednesday w/freezing rain showers. That said...it's a matter of one or two degrees so I'll be shocked if literally that whole area ices, but consider yourself on guard! Worst icing farthest north. Travel impact, not power outages.
In the mountains of NH and ME to Northern ME, Wednesday will be cold enough for 1-2, 2-4 and 4-6 inches of snow. Following Wednesday's strengthening storm to our southeast that delivers our combo of snow/freezing rain/rain, winds kick up Wed evening and night, driving wind chills subzero overnight in Northern NewEng. No damaging wind expected.
But what about those Xmas Eve & Day snowflakes? A quick-moving disturbance overnight Thursday night will deliver snow showers and perhaps a coating to 1" of snow with some higher amounts in the mountains into Christmas Eve *morning* before sun comes out for the afternoon.
Christmas Day continues to look like a prolonged period of light snow and rain with the placement of the rain/snow line TBD but perhaps starting somewhere near the MA Turnpike and drifting north during the day as temps slowly climb near 40 there, 30s north.