Kate, I'm just down the road from you, and I did bring most of my orchids indoors last night. They will stay in tonight too, then go out once the night temps are in the 50's again.
But you can protect them from the worst of the cold with something as simple as an old sheet, curtain or blanket. If you can cover them to protect from the dry cold wind that is blowing right now, and retain some of the heat that rises from the warm ground, they mostly should be fine. Better yet, frost cloth from any good nursery or the big box stores will both protect your plants and let lots of light get to them if you forget to uncover them, or if there are several cold days in a row. (let's hope not!! but this winter sure has started out early with the cold)
I use bulldog clips (from the office supply store) to hold my frost protection in place. They're really handy for a lot of things around the garden.
