Could probably do a poll for best 1-3 week winter period but I wouldn't do it cause there's probably a lot I don't know about. These are the ones that stand out to me:
Feb. 7-19, 1979 ( I wasn't alive for it but seems absolutely insane)
Jan. 22-26, 1987 (too young to remember, but also seems great)
Jan. 17-21, 1994
Jan. 7-13, 1996
Jan. 20-30, 2000
Feb. 6-28, 2003
Jan. 30 - Feb. 10, 2010
Feb. 14 - Mar. 7, 2015