I also live up here in Alberta ne of Edmonton so I know exactly the winter conditions you're going to experience.
First of all, I open the coop door and my chickens are outside during the day all winter except for during blizzards. I have now and have had australorps, ameraucanas, marans, silkies, seramas and leghorns so I've had a good mixture of breeds. I feed them a mixture of layer pellets and whole wheat and also give vegetable scraps, and cat or dogfood for a treat.....mine come running as soon as they hear me getting the dog food from the garage....lol . I always have the feeders full of food so they can eat any time, and never wet it down. Also have feeders in different locations both inside and outside the coop.
They get fresh water twice a day in winter and I chop up garlic and give a dash of ACV to keep them healthy. That usually prevents any illnesses, but you need to watch closely for mites and lice. If your chickens are listless it could be one of those pests sapping their strength. Worms are not a problem usually here in Alberta. Also any chickens going into their second winter could be moulting.
I use a 100w light bulb only to keep them warm and to give them the necessary light in order for them to lay in winter, only using the heat lamp when the temperature drops down past -30. If you're worried about freezing combs just slather on some vaseline.
My roosts are wide enough that they can sit on their feet and cover them completely to prevent frozen feet.