Some towns commemorate Christmas year-round—they have to.
Whether it's North Pole, AK.; Bethlehem, Penn.; Silver Bell, Ariz.; Eggnog, Utah (yes, that's real); or Rudolph, Ohio (or Rudolph, S.D.; Rudolph, Tenn; Rudolph, Texas; or Rudolph, Wis.), some towns are permanently shackled to the holidays. For the record, Rudolph's friends Vixen, Comet, Cupid, Dasher, Donner and Blitzen also have towns named after them (in order, they're in Louisiana, Arkansas, Nebraska, Georgia, California and Oregon).
Idaho has its own year-round Christmas village: Santa, an unincorporated town in Benewah County, just southeast of St. Maries. Needless to say the post office at Santa (area code 83866) is a pretty popular place in December.
If you're inclined, you can also visit nearby Christmas Valley, Ore; Holly, Wash.; and Shepherd, Mont. Anytime you're anxious to get winter started, you may want to visit Snow, Idaho, in Nez Perce County.