SCORE!
The pots are very typical of those you see @ the Big Box stores, with some nice, some *very* nice and some the same as anywhere. The big deal for me is that I only needed the lower end pots and didn't need to spend anything on shipping as they were no more than 5 miles from me and I simply dropped by and picked them up. Thank you again, Lynn!
The deal with pots and freezing temps is the water the pot absorbs - and just about any clay pot will absorb some water. Just like your pipes - if they freeze, the ice crystals expand and will break the pipe. Ice inside the pores of the clay will do the same thing. I would guess that a very low porosity pot might work, but I never used anything like that outside that could possibly freeze.
As added protection with these types of pots, I use a waterproof sealer on the inside and on the bottoms. Although it probably makes them much like plastic pots for the plants at that point, I still have the terracotta on the exterior. But water is usually what makes them break down over time.
