I have my coop full of wood chips and hay. I have been keeping the water in the run area but I do need to find a better solution. They tip it in the coop and I can't have it getting wet in there. I did have a small waterer in a pan, but they wanted to roost on it. When I had it in there we did have a very cold spell.... 10-20 degrees! The water actually didn't freeze, so that tells me the coop will work for them.
I've been bringing them into the garage for the past 2 years. It got so messy in there last year when they kept breaking out of the make-shift coop that we decided not to do that this year. The lawn mower will never be the same... I'm a bit nervous about keeping them outside, but all the breeds I got are selected because they are very cold hardy. There are 6 of them to keep each other warm and the coop is pretty good. I tried to insulate the walls with that foam insulation... STUPID mistake. They ATE it!
I've read a lot about the deep liter method, so that is what I'm doing. I've caulked around the outside for any drafts on the northern side of the coop. I did leave some slits around the southern facing windows for air though. I just can't be sure if I'm letting in too much cold or if it's the right thing to do for air circulation. I've read many warnings about the need for circulation in the coop, but it does get COLD up here. I think I'll put some kind of cover on the slits to keep direct wind from blowing in.
I don't have a heated waterer, but I'm home all day and I'm neurotic about them and like the idea of checking on them a few times a day. They are so happy to see me come out with warm water and oatmeal. I don't provide them with any heat except an occasional milk jug of super hot water. I place it in the corner of the coop to dissipate some heat when it's super cold. I don't supplement light for them either. I did when they were in the garage last year and they kept on laying. I haven't had more than 1 egg a day lately. They need a break. 2 of them are in the first year, 3 are going on their 3rd year and 1 I'm not sure of because I adopted her. I'm guessing she's about 2. They all seem very happy and healthy. So I must be doing OK for a city girl.