the plant wont like temps around 60 but it will still live. anything near the low 50's is cutting it a little close. below 50 degrees = death(unless your plant is a tree)
like elnene said, an electric blanket or heating pad touching the soil would work wonders, I've witnessed a plant survive almost freezing weather with a heating pad wrapped around its bucket. but if it freezes your plant will probably get damaged or killed. I'm going to test my plant this winter and see how much a heating pad can do, im sure the plant will be warm if its soil stays warm.