i have about 20+ vandas and in Orlando... the weather has been terribly cold so i have my vandas on a clothes rack so i can cart them in and out of the house.... not sure if this is a possibility for you but i would def bring them in and try to get them watered once a day...
Your vanda rack looks great. Does it have a tendency to tip easily? How wide and high is it? What is the length of the feet (base), and what size pipe did you use?
I could use one like that in my garage when I want to spray my Vanda plants. I grow in my basement and don't like to spray inside my home.