At any rate, thankfully I thought about the hummingbird feeder and yes - found it was also frozen. It is now thawing as I write, and will be ready for them when they venture out at dawn. I feel such a responsibility for them, especially during the winter like this. We just haven't had weather cold enough to freeze their food before last night.
So when my husband gets back, he'll have to get out his invention from last year: a thermostatically controlled hummingbird feeder heater. The name needs some work, obviously, but it works like a charm. Until then, I will check their feeder several times during the day and bring it in at night. It is the least I can do for these special, precious little dears that winter over with us.