When will lightning strike? When will someone run a red light and T-bone your car? Will the risk of that stop you from driving to the grocery store? We all live with some risk every day. The odds of your losing one to a predator is greater than getting your car T-boned, obviously.
No one can say how dangerous it is in your circumstances for them to free range. Some of us can go years between predator attacks. Some have disasters about as soon as they try. A lot of us that normally free range occasionally lose one but accept that as the cost of them being able to free range.
My parents kept a free ranging flock way out in the country, in a pasture right next to a woodland. They would go years between losses to predators, but occasionally a fox or dog would take an interest in the flock and have to be dealt with.
I keep chickens in a different situation and take a lot more of an interest in them, including locking them up every night, which my parents never did. I had two losses in three years, until this summer. Then someone dropped dogs off for the good life in the country. That cost me 8 chickens. A fox has taken an interest in them, picking them off one at a time. That's another four gone. I have not managed to take care of the fox yet. Those are tough. A few days ago, I lost my first one to a hawk. Lightning obviously struck this summer for me. They are penned in the run now. I feel the odds are if I can get that fox, I can probably make another pretty good run free ranging without serious problems. Probably.
All I can say is that you may be OK but you also have to be prepared that you may lose some.
