Few questions about a possible upcoming trip in the fall...
How is Woodstock in November?
Are the shops and restaurants open?
How is the weather?
Woodstock is pretty much a year-round tourist town, with a sizable local population. There may be a few places that close or shorten their hours during the winter, but most places are open. Depending on just when you go, you can expect the weather to range between unseasonably warm, and cold, wet and miserable, with a slight chance you'll find fresh snow. Cool with an overnight frost is pretty typical for mid-November.
What places do you recommend visiting during the fall foliage?
If November is the only time you can do this vacation, nowhere in upstate NY will have foliage at that time.
You would need to look well to the south.
What months are good for fall foliage?
October is good. Depending upon what part of New York State you will be in it could be throughout the month. This past year the colors were later than usual.