In my business I am able to take time off as I please - that, of course, is one advantage of not being in a business by myself
But scheduling some level of downtime is a good discipline. It doesn't have to be Christmas, of course, although that can be easier as people sort of expect you to be shut. Until you are an online store. Or IT support.
Now at certain stages of business life that might not be so easy. Within those stages, moving out of them ought to be a priority.
For me, it was always a question of planning, and a compromise about how long I want to be away from the desk. In the early days we didn't employ people to provide support over the holiday period. We did it ourselves. But obviously, that didn't necessarily involve much work, unless something broke.