I just googled it. Lots of good info. The one I liked best is called Winter hummingbird feeding and nectar tips. Birding.about.com. They mixed the nectar different for the cold weather. 1 part sugar to 3 parts water. Feed them early in the morning when they need the most energy. Bring the feeder in to thaw and put it back out later. Different suggestions for a warm area for the feeder. On a windowsill of a heated room, In a closed area,etc. Easier for you to read it for yourself and decide. I just took my feeder down today. Mine left in early Sept. when it got into the upper 90's here for a few days.

That's the second out of place rufous I've read about this week now. The first was captured by a rehabber and they were looking for a way to ship it....

I don't know if you can save yours or not, it's so early in the season. Here, during freezing weather, there are various things to do like keep back up unfrozen feeders and swap them out when the first freeze. Bring them in at night, set an alarm and get them back out at least a half hour before daylight in the morning (which is what DH chooses to do). Duct tape disposable hand warmer packets to them will help for approx. 6 hours. Christmas lights wrapped around the feeder can be enough heat to keep them thawed.

Of course in my climate I'm talking about for a week or so a couple of times a winter where the annas regularly winter over - the syrup in the feeders will begin to freeze after a few hours at about 28F.

I wish I knew how you might save yours, I wonder if there is a licensed rehabber available in your area. I think that's the only legal way to attempt to intervene.

Here is a link that might be useful: Wayward Rufous this week too

One of the other suggestions was to put a spotlight on it to keep the feeder warm. I'm not sure how the hummers would react to that.

I just noticed KING 5 TV Seattle had some tips on its news site today too....in view of our week of colder than norm weather we're experiencing...

....another method to try is plumber s heat tape. These flexible electric tapes are similar to a flat extension cord and can easily be wrapped around and taped to many types of feeders

....hang a trouble light nearby the feeding station, or from the bottom of the feeder. This is the light commonly used by car mechanics, or garage enthusiasts. It has a little cage around it and a hook at the top. Depending on the watts, it can put out enough heat on those especially cold nights

But again, this is a milder climate, a cool Z8. You are still in Fall preceding your much harsher winter. I don't know what the habits of rufous are in your area, but those that had been feeding here haven't been seen since July, I've only Annas at my feeders that stay year round.