Here are a few restaurants offering vegan meals on Christmas in the USA:
Hangawi, New York City, NY http://www.hangawirestaurant.com/Holiday%20Menu%202016.pdf
Harvest at the Bindery, Portland, OR (Christmas Eve) http://harvestatthebindery.com/index.html
Herban Fix, Atlanta, GA http://herbanfix.com/events
Mother of Pearl, New York Ctiy, NY http://www.motherofpearlnyc.com/
Raven’s at The Stanford Inn, Mendocino, CA http://ravensrestaurant.com/ravens-christmas-dinner-2016/
Su Tao Café, Malvern, PA http://www.sutaocafe.com/event.html
Vegetable Garden, Silver Spring, MD http://www.vegetablegarden.co/