Wow, you have really had some cold weather! I am right on the line between 7b and 8a but I buy plants for 7b since the average temperature puts us in 8a, we still dip down, and certain z8 plants would die if I had them and I would rather not loose plants.
I have seen frost a couple of times and we have been in the seventies all week. We have a powerful cold-front moving through right now and we are supposed to get down to 35! The only thing I have to bring in is my mandevilla. I'm pretty much ready for the cold weather, plant wise, my bones are never ready!!