Yeah, the ivy is pretty cold hardy. I let it freeze if it's above the lower 20s. But being in a pot makes a difference. I had a sedum get badly damaged last winter and it ordinarily handles freezing really well. What was growing in the ground wasn't damaged. And I had two native cacti plants of the small barrel type get killed last winter. They obviously survive quite well in the ground. Also, there is my preference for clay pots. While they give better insulation than plastic does, they are prone to flaking, cracking and even busting apart when they get frozen. It's sort of become part of my winter activity to be moving potted plants back and forth from inside and outside depending on the forecast! It's when the weather folks miss those forecasts by too many degrees that I get in trouble
:(.
