Chris,
There are some "sissies" that can't take the cold but you are lucky the snow arrived first to cover the plants. That will definitely help. Here we went from lush wearm rains to WINTER in a heartbeat and record cold with NO protection. It has been an education as to which ones do well and which ones look damaged. Was leased that most of my lines are pretty healthy. However, things derived from 'Commander Hay' or that line are almost always damaged.
Maybe these sort of conditions are good for us every now and then so that only the hardiest plants are preserved and used as parents for the next generation.
Kevin