It's called touring... . 4200 miles is a bit much, but lots of people do very long distances. A couple I know of, for a retirement celebration, cycled to Indiana and back. 1000+ miles one way.

There are lots of touring bikes available that can carry a heck of a load. And many for less than $1000. I'm sure he went through some tubes and other minor repairs though. 60-65 miles a day doesn't sound like too much though, if he averaged 10 mph that's only like 6-6.5 hours a day of riding. Sounds like fun .