Sad, but a very good lesson for modern preppers. That family did not survive their flight into the wilderness. Their line went extinct. The best that can be said for them was that they lived a while before they died. Survival is about continuation. The old generation can only truly survive through a new generation. Without that, their journey into the future stops.
No problem. Works in Arkansas. Just make sure the kids have someone else to marry up with so you don't start havin' chinless chilluns' with a third arm growing out of the center of their back. Once your family tree starts lookin' like a telephone pole, you'll probably want a little dose of hybrid vigor now and then.