We're planning to take ours down this Sunday, since Saturday is Jan. 6, the start of Epiphany in our church calendar. We didn't put our decorations up until Dec. 10, since we didn't have time before then.
When I was a child, my Episcopal church was so strict about not having "Christmas" until "Advent" was over that it didn't put up the decorations until after the last Sunday in Advent, and the priest urged all families to do the same. So my parents never put up the decorations until Dec. 20 (which is after the third Sunday in Advent) and didn't take them down until Jan. 6.
Now DH and I go to a Methodist church that has decorations up soon after Thanksgiving - but he and I still tend to wait until after Thanksgiving weekend to decorate our house.