We're very lucky to have the setup we have. It just happens to be perfect for free ranging chickens with about 1-2 acres of grass surrounding the house and the rest in woodlot. The chickens are never more than 30-40 yards from the house/garage/cover.
The only drawback is raccoons and possums, which I monitor via a gamecam and hunt as soon as one wanders around. I believe in active vigilance in this area, since we free range. As soon as I discover a predator is visiting at night, it usually only has a life expectancy of a few days.
I know their are risks inherent to free ranging but I'd still rather let them free during the day. So far, a year into it and no losses. But that can change in a blink.