Agreed, but the timing of the water is important. Late October watering is recommended to prevent winter desiccation. By this time, the tree should be fully dormant and ready for winter. For less tender plants, mulch the soil around their bases to protect the root system from extreme cold, and from fluctuating spring temperatures. If possible, encourage a good snow cover around the plants.
Snow is an excellent insulator.
As winter sets in, the tree has become fully dormant, and will not come out of this state until the changing environmental conditions once again stimulate growth. This type of dormancy also applies to seeds of trees grown in this area. Many hardy trees produce seeds which will not germinate in the fall. If the seeds were to germinate in the fall, many of the young tender seedlings would be killed by the severe winter conditions. The same growth regulators which bring on dormancy in trees also prevent growth of seedlings in the fall.