Tiger, that really is amazing, I had no idea. Hummers must stay around all year in my area. I've seen them in Feb visiting camellias. Snow is extremely rare here.
There are plenty of frosty nights here, but the usual low for most of the winter nights is about the same as your low last night. The last time the temp was below 70 (21-22 C) here was in May I think. Stay warm up there!
Bea, do you keep feeders out all year?