Hiya, and welcome to BYC! 
I live in Wisconsin so know what you mean about cold. We're Zone 4 too. We raise silkies, and I don't know meat birds, so I'll defer to @sourland above or whoever knows what those are. We heat our coop to 40F because I'm a wuss and won't haul water plus, some of them don't fair well in the subzero temps.
As far as predators, we border a forest on the back side, and farmers fields on the others. We have every varment including bear here, but knock on wood, no issues of losing chickens to a wild animal in several years. Our coop is a finished Amish garden shed, so nothing can get in, and they free range by day.
We have two dogs, a border collie and a corgi, that are as good as any LGD and keep the animals away. We have a dusk-to-dawn barn light on an old power pole that lights up between the coop and house (120 feet), numerous solar motion lights, huge wind spinners, and several Blink outdoor cams so we know what we're dealing with.

I live in Wisconsin so know what you mean about cold. We're Zone 4 too. We raise silkies, and I don't know meat birds, so I'll defer to @sourland above or whoever knows what those are. We heat our coop to 40F because I'm a wuss and won't haul water plus, some of them don't fair well in the subzero temps.
As far as predators, we border a forest on the back side, and farmers fields on the others. We have every varment including bear here, but knock on wood, no issues of losing chickens to a wild animal in several years. Our coop is a finished Amish garden shed, so nothing can get in, and they free range by day.
We have two dogs, a border collie and a corgi, that are as good as any LGD and keep the animals away. We have a dusk-to-dawn barn light on an old power pole that lights up between the coop and house (120 feet), numerous solar motion lights, huge wind spinners, and several Blink outdoor cams so we know what we're dealing with.