Connie, I did take several of mine into an unheated garage last winter and I'm also in zone 4. I did not cover them. I did give them a small amount of water twice over the winter. I made sure the water was really cold though. They received some indirect light during that time. I only took them in because they were varieties that I knew didn't do well with a lot of moisture in the spring. Otherwise I just put my containers up against the house and they're on their own.
I didn't lose any that I brought in the garage, however, they did curl up into tight balls. But when I brought them out in the spring they bounced right back and look fantastic.
I agree Susan, it's way too much work to haul everything in for the winter.
