Anna's Hummingbirds will stay the winters here in the Pacific Northwest. In the summer, we'll get transients in along with Rufous Hummingbirds. Over the winter, individuals will stake out a territory.
This is "my" local resident. When it gets below freezing, I'll rotate two feeders during the day. When one starts to freeze, I'll take it in, and replace it with one that has been inside to thaw. Little bugger will suck down a lot of "juice" when it gets cold. When he's not at the feeder, he'll perch in the tops of the trees in the background:

That’s neat. We can’t change the world, but we can at least make part of it better.

Good Man for helping the little guy out.

-10 here with the ground snow covered. Been feeding my resident birds and a dozen whitetails for a few weeks now.

I saw a picture the other day where someone wrapped a heating pad around their feeder to keep it from freezing. It worked and the birds kept coming.

Have a friend that wraps a towel around her feeder, then adds those chemical footwarmers.

We have 3 feeders and the hummers are thirsty buggers.

do you adjust the solution for the colder weather?

instead of 4:1 , perhaps 4.50:1

Re: “hanging in there”:

I read an article about hummingbirds in the Andes. At night they go into a comatose state to conserve energy, hanging upside down from their perch, I believe. In the morning they shiver violently to get their body temperature up. They have only enough energy for one attempt – if they don’t make it they die.

While we've been around freezing at night this week, we had warmer temperatures last week. I was home due to having my HVAC replaced.

There was a bird sitting fairly high up in the tree in my front yard. After a couple of minutes, a hummingbird started flying around and hovering in different places around the other bird. The other bird departed a few moments later, and the hummingbird took over the highest branch of the tree. Fun to watch.

We have two or three that visit pretty frequently as well as lots of other birds.

Sometimes it seems like I spend more on birdseed than I do on dogfood.

Today I actually got my first ever shot of a Hummingbird, also an Anna. Had just one shot at it. It was behind the feeder, came around to the front, I hit the shutter and zip it was gone...

Untitled by Wayne Wilson, on Flickr