In years past my husband always insisted that we leave the tree intact until Epiphany. That allowed time for film to be processed, printed, picked up and the results viewed. If the photos didn't turn out well, the tree was still there for a re-enactment. Now that we have digital cameras and instant photos, we're at a loss to know when to take the tree down.
A more important question at the moment is, "When shall we drag artificial tree sections down from the roof space, try to remember how to assemble them and figure out all the other hows and wheres needed to end up with an acceptable looking Christmas tree which will remain in a vertical position?"