I read this in a Q&A on the web from a person wanting to buy pots and wanted to know which to buy that may not crack in winter:
Failing spending lots of money, you could always place your plants inside large plastic pots & put them into your ceramic pots. If you allow room between the two & perhaps place foam peanuts in the space (cover the top of the peanuts with moss to hide them), the ceramic pots won't crack. It's when the clay is saturated with moisture & then freezes, the frozen water expands & since it has no where to expand into, cracks. I'd make sure any water given to the plants can drain freely out the bottom of both plastic & ceramic pots so it won't accumulate in the expensive ones.
My experience one winter after moving to zone 5b in WA was to line a ceramic pot with black garbage bag from top to bottom (with holes for drainage). This was to help prevent moisture from sitting on the sides of the pot and help prevent cracking. Also since it was winter, my watering was minimal (as the pot contained succulents) so soil was never soaked.
You could experiment pinkruffles.
