For what it's worth, here is my suggestion. Use your sewing machine to make a small circular eyelet such as what you would use on a belt. You could slip the button shank through that hole from front to back. There are little metal clips used on buttons you want to remove prior to dry cleaning or laundry. That clip will keep the button upright without tipping downward. If you look in your button box or on the back of some cards of buttons, you probably have the clips available to quickly experiment.
In any case, your holiday quilt is cut and the embroidery is very nice. May your bobbin always be full ;-)