Half of LED lights have failed when the temp went below 30f

I have many 60' strands of LED lights on my house and a 22' tall blue spruce. They looked gorgeous. However, as the temperature has recently plunged to near 25f after a long period of warmer temps here in Knoxville, I have many strands that failed on the same cold night. Most have sections in strands where no lights are lit. I have one strand that is very dim. I have tried to use the volt meter and replaced bulbs I thought were bad. I was getting some strange intermittent voltage readings so I'm wondering if some sockets are suspect. I have never seen this type of issue going into colder temps. any help?