I have heard those stories too but I haven't yet experienced this yet. Broodies typically do eat 1-2 times a day along with their bathroom breaks, mind return to their feeders but they also have always brooded in the nest box for me (fortunately). Several of my birds have found 'secrete' nesting spots to lay their eggs, and if they had gone broody during this time I am sure they would have brooded on those locations and I would have had a very difficult time finding them. I suspect some birds would return to the same place to eat/drink if the brooded in a secrete location just as my hidden nest layers would eat/drink and hang out with the regular flock then lay their eggs elsewhere.
I have lost 4 birds in my 3 years of having my own chickens, 3 were obviously predator related finding blood and a pile of feathers or even seeing the attack itself. One of my favorite young roosters just vanished one night in the middle of winter, I suspect he roosted outside somewhere and a predator got him in the night. Count yourself lucky if you don't have Raccoons in your country, they are horrible animals when it comes to chicken predation.