I personally don't free range. It's safer for them that way. I also have a dog with a history of killing chickens. I don't trust her around my birds anymore. My chickens live in a covered run (and coop of course) all the time.
I have a family member that has a large coop and run and I often give them my chickens if I can't find them homes or just if they need a warmer place during winter. They occasionally free range, but only under supervision. That's also how I lost my rooster. They have a fox living in a near by forest. And hawks. No matter how much I tell them to get a net on top of the run or fix holes in the fence, they just don't care enough.