I think you are going to find that with a lack of human presence except for once a day you are going to have many, many losses to predators. Heck, predators come out of the woodwork for chickens even when kept near a house with plenty of human activity. Chickens that are off alone like that are going to get picked off fast, especially if they are not secured in a very secure coop at night. If they are out free ranging during the day they are also going to disappear fast. I'm not trying to sound discouraging but it's just reality. A rooster can be a good warning system for hens to try to get to cover but he cannot protect them from fox, raccoon, coyote, bobcat, roaming dogs, etc. etc. The only way I'd keep a flock off alone like that is if they were in a very, very secure coop and run, otherwise there won't be a flock for very long.