I don’t have a freezer with this much space. Is it OK to use an ICE bath to quench the tires?Cutting the tires isn't for the purpose of sizing -- you size tires by mounting them and stretching or shrinking them with heat/cold.
Take the valve core out of your left rear and place the tire in the sun until it is hot. The put it in the freezer for a bit. That'll shrink it some. Repeat if necessary to get desired stagger you want.