Oleg Konovalov wrote:

Are you saying that the higher the elevation, the more chances of snow?

In this case, how about the Prospect Mountain?
On their web site they claim that they have snow when nobody has it,
although they are a way to the south from Stowe.
Is that a good place to stay and ski with the family for 4-5 days ?

OK, suppose it's warm before Christmas.
Any good places in Canada which are not too far (Quebec, Ontario) ?

Yes, higher elevation improves the chance for snow. So, for example, in
New Hampshire, Great Glen Trails has a slightly better chance of snow
than nearby Jackson (although Jackson itself has a pretty good chance).
In southern Vermont, Prospect Mountain stands out as a place with
significantly better chance of snow than any place nearby (or even
compared to places an hour or more further north).

The problem with the time of year under discussion (before Christmas) is
that the odds are not very good anywhere in northeastern North America.
That time of year, there is a significant possibility that you could
go all the way to Camp frigging Mercier (north of Quebec City) and find
little to no snow.

At the Big Three northeastern-U.S. cross-country ski towns: Lake Placid,
Stowe, and Jackson, you probably have, in January+February, about a 90%
chance of having good snow conditions. But, in mid-December, the odds
are more like 55%. (For Prospect Mountain, I'd guess something like 80%
in the heart of the winter, but something like 45% for mid-December.)
The best odds for snow within the northeastern U.S. are at some of the
less well known and less convenient places: Great Glen Trails and The
Balsams in New Hampshire, or Hazen's Notch in Vermont, so that might get
your odds up to, say, 60%.

In northeastern Canada, the best chances of early-season snow (maybe
67%) are Parc de la Gatineau (which you went to already),
Mt-Tremblant/St-Jovite, and possibly Val-Morin/Val-David (i.e., Far
Hills Resort), possibly Mt-Ste-Anne. And, of course, Camp frigging Mercier.

Lew Lasher
Cambridge, Massachusetts and Stowe, Vermont