Certified GKH Gardening Expert
As long as they are in the ground, most likely they are fine. Plants need far less water in the winter than in the summer and the ground normally holds more than enough to keep them alive.
The issue I see could be that without snow, the plants may not have had the insulation they are accustomed to, and that can hurt the plants. If you fear the plants may be dead, this article will help you tell that: