Model X Snow Tires

The problems will likely be brake clearance and carrying capacity along with wheel offset. If the tire's RPMs are the same (within 2%), there won't be a problem in that area.
However, my strong recommendation is for a second set of wheels and tires because every time you mount and demount tires, there is a chance of damaging them. (Used wheels are fine for winter since they tend to get banged up anyway).

The rolling diameter isn't the same as on the Model S. It's about 1" bigger.