No advice really. Just keep doing as your doing. Chickens dont need anything special in the winter. Sometimes when it gets super cold I toss cat food out to the flock to give them a little lift in protein to help keep them warm.
I just move my dog's house close to the pop door of the coop during the winter months and let him blaze the trails elsewhere...I'm very much into no wasted motions in my choring. The texture in the path made by his paw prints makes for good footing for the chooks and he goes all the places they like to go, so it's a win/win.
I am going on my second winter having chickens up here in Alaska. I really don't do much different in the winter, which can last 8 months. I do light my coop and run. The girls still do take a break from laying even with lights. When the snow gets crusty and icy, I will put down a layer if straw on the pathways. You would think when it was -20 they would stay in their coop, but they want out every day. They are a hearty bunch
Mine like to come out too...I think it's just because they are nosy and love their freedom. If the snow doesn't cover the ground, they are out foraging for greens per usual.... this was in the first snow last year and they acted much like the dogs~"Snow? What fun! Let's go out and play! "