Depending on conditions (whether the soil is well-soaked by available rains or not in the fall), I water as needed right up until plants drop their leaves, or are otherwise gone dormant. This is especially important for newly planted trees and shrubs, and any very young or very old specimens, which suffer most if not well-hydrated during stressful winter conditions. Evergreens are another group needing good hydration pre-winter, to help stave off the effects of drying and burning on their persistent foliage during the coming months. Is the ground well-moistened or does it need you to contribute? Are there vulnerable new things in particular to tend to with another drink or two?