you need the 2 miles of concrete or hard compacted 'bush' if you want to walk away.
Only if you want to use the aircraft again. As a couple of 777s have demonstrated, all you need is a reasonably flat surface. You'll even stop in a much shorter distance than if landing on a runway. it might be a bit of a rough arrival but it's quite survivable.
Your real problem are the zombies. They're gonna get you.