As for the "more snow", something else I explained was happening, the
Rutgers lab shows this clearly.
Winter starts at the end of December and lasts until the end March
According to your reference there is an trended increase in NH snow cover in December, January and February and generally declining trends March through September. What isn't apparent, is what significance you attach to this? We can demonstrate that it isn't relating cooler temperatures over the NH in the same periods neither monthly, seasonally, nor annually.
Snow cover increases ≠ colder temperature trends what it does indicate is more moisture in the atmosphere making it available to condense out as snow (instead of rain) when the temperature is appropriate to produce snow.
As a side note, some seem to be repeating the rather common trope regarding it being "too cold to snow," in actuality this is not true. What tends to prevent snow in extremely cold environments is the fact that extremely cold air simply cannot hold much moisture and will release that moisture long before it gets extremely cold.
1
Most snow comes from storm systems that erupt when very cold, dry, dense air masses roll over the top of a warm, moist and low density masses hugging the surface. As the lighter, moisture-rich air mass bubbles up through the overlaying frigid air the mixing generates the storms that release rain/snow. This is easy to visualize in summer/spring storms, but it should be understood that a large mass of air in the mid-thirties(F) is a "warm, moisture-rich air mass" compared to the sub-zero air masses rolling down from more northerly regimes.
If you are really interested in increasing snow cover in some Boreal regions in the colder months of the season, the question that should immediately spring to mind is: "why do we have increasingly more warm, moisture-rich air masses hugging the surface in these high northern regions at these times of the year?"
IIRC, these explanations and discussions are the same that have occurred each winter for the last few years.
1. Snow falls do occasionally occur in Antarctica, where average suface temps often hover around 70 below zero. The snows rarely amount to tenths of an inch, as the amount of moisture that can be held in such "warm air masses" is very small.