It's amazing what people can do when they apply themselves. It really is. A single man in our day and age is regarded as helpless without force of numbers, when in fact nearly any damn thing that mankind ever achieved worth talking about was usually accomplished by one man working alone.
This guy sounds like he's not even in the physical shape needed to do this kind of work but just look at how far he got. Very, very impressive. Another couple of months he'd have something under there comparable to a Cold War L-4 installation. He could have gone to a 1200 square foot multi-level shelter with his available space and existing layout. That place would be awesome with a little more work.