Yeah, having to maintain a half mile private road would be a handful to say the least. I have a neighbor who has a driveway almost that long...he kind of gave up maintaining it after 10 years or so, now just parks at the bottom of the hill and uses a snowmobile or ATV to get to the house. A 4WD truck or Jeep could probably get up there, but I don't think he has one. Most of the vehicles marketed as "SUVs" today probably wouldn't.
I hope his insurance is paid up, there's no way a fire truck (or any other emergency vehicle) could get up there.