Peg,
It really depends on the year. Last year many still had leaves in January, because we had such a warm Fall and Winter. This year they have been whip-sawed with hot weeks, and cold weeks, and some are already bare, or nearly so, which some are still putting on new growth. On average most should be dormant by mid-November. New trees, esp. rooted cuttings in their first season seem more interested in growing rather than going dormant, and usually have their leaves longer. I keep feeding them as long as they have leaves, to help size them up.