If not using gizmos or blow through extensions for the skimmers, but rather, are using a large jug, it should have as much or more "give" than the water expansion when it turns to ice. This "give" will absorb any pressure exerted by the expansion and prevent it from cracking the skimmer body.
There are several ways to fill the jug but it should float some above the surface, not sink. The expansion is greatest near the surface of the water level. Many will 1/2 fill the jug with water but that, to me, makes no sense. That water will freeze too. Some use antifreeze. but if the jug cracks, there goes the antifreeze. I prefer using small rocks. If the jug cracks, the rocks normally won't get through the crack. I also turn the jug upside down with the cap on tightly. This traps the air inside.
Scott