Christmas log, Bûche de Noël or Yule log if you prefer, is a traditional French dessert served, unsurprisingly, around Christmas time. The popular (but almost certainly wrong) origin of this dessert is that Napoleon I of France proclaimed households in Paris should keep their chimneys closed during winter in order to keep out the cold air and, not being able to use their fireplaces, this symbolic replacement was created.
Can it be Frozen? Yes, for up to 1 month.
Can it be prepared in advance? Yes, it can be finished up to 1 week in advance.
Will leftovers be nice? Yes for up to 1 week if kept out of the fridge, 2 weeks if in the fridge.