Wintertime feeding of hummingbirds has been a family goal for quite some time. Providing food in freezing conditions was something my father-in-law solved years ago. You can read about that winter freeze in an article written by my mother-in law.
This is our current model made from a plastic pot and some Christmas lights. With all three lights lit it will keep the food from freezing down to around 20 degrees.
You want to use old fashioned Christmas lights, not LED’s. The heat the bulbs produce is what keeps the food warm. We took three sockets from a string of lights and wired them to an extension cord.
Nothing fancy and in warmer weather the pot/light assembly retires to the garden shed. Everything we used was lying around so our total cost is just in time.
When we used to live in Tacoma with a more moderate climate our winter feeder hung over a Sasanqua Camellia (which blooms in the winter) and the hummers would perch on a branch right under the feeder. Close to food and probably soaking up a little heat.