If you want to experience an old-fashioned Christmas which will also be white visit one of these towns:

Woodstock, VT

Old Sturbridge Village, MA

Stockbridge, MA

Canterbury Shaker Village, NH

Bath, ME

Grand Lake, CO

Durango, CO

Prescott, AZ (may not be white)

Cedarburg, WI

Massachusetts and Vermont aren't necessarily snow covered by Christmas time (??)

I'm surprised Canterbury Shaker Village is on the list. It appears to be open in December but guided tours ended in November. If one wanted to come to NH I would suggest finding a small town with old fashioned Christmas Eve services. Choir might be slightly off key but thst's ok. Most ski area will probably have snow but you might have trouble finding a restaurant that is open. Christmas lights are already on some homes. Most of the festive events start this weekend but end close to Christmas. This weekend in Canterbury there is Christmas with the Cows at Brookford Farm which will have a German market. Clough tavern, now a private home, opens to sell local arts and crafts and garlic items they grow and make. Near I93, exit 17 and technically Canterbury I think you will find Mathew Mead and others selling wonderful things in an old cape.

I think Durango is more likely to have snow for Xmas these days but Woodstock is a bit more comfy.

General tip, is if you want snow look at high altitudes.

Buffalo might have some snow left by then.

Buffalo always has snow but does it have an old-fashioned Christmas celebration?

what is an old fashioned Christmas celebration?

We've enjoyed Christmas Prelude in Kennebunkport in the past and will enjoy celebrations this weekend in Falmouth MA No guarantees of white.

Maybe Telluride?

Grand Lake is nice, but I'd recommend Devils Thumb Ranch, also in Grand County. Everything you'd want is there: great food, service, amazing setting, horses, spa, skiing, etc. You don't really need a car if you take Amtrak from Denver to Fraser, the Ranch will pick you up.
We have gone to DTR since it was just a barn in the 70s.
They have a huge property, and snow should not be a problem.

https://www.devilsthumbranch.com