I've got my chickens on cultured deep litter comprised of leaves, yard debris, wood shavings, twigs, bark, pine needles...you name it, it's in there. I rake leaves in the fall, compress them into trash bags with holes punched for air and use them for bedding in the winter.
I haven't cleaned out the coop litter in three years now, it just composts in place and keeps them busy, warm and dry when confined due to snow.

Using a heated water bowel elevated out of the litter on a step stool right now but plan to build a fold down platform before next winter for this purpose. I have a hoop coop made from cattle panels and recycled wood scraps, so it's easy to scrap on pieces here and there as I need to adapt.
We've been getting subzero temps here and the birds are snug as a bug, plenty of ventilation, clear tarp on the coop to let in winter sunlight and that has made such a huge difference since last year when I had a silver tarp.

Here's a pic with a shot of the clear tarp....has made such a huge difference in this year's winter coop!

Feeding fermented feed once a day and throwing down apples and a few handfuls of this or that in the litter to keep them busy when the snow keeps them inside too long. My flock free range, so there's no run to describe...the pop door never closes and they come and go at will. They have a chicken dog that guards them at all times and has sleeping quarters next to their pop door.
So far winter has been good, even with subzero temps. No frostbite on any birds and all seem comfortable on the roosts.