Hadn't seen this thread before.

In my opinion, the idea is nuts. I've toured, loaded, at 125 miles a day for four successive days. I was fit, accustomed to riding c. 10000 miles per year, and at the end of that four days I was very tired. I've done a 600-mile five day sportive, and I was in reasonable shape at the end. I've toured, again loaded, at 1500 miles per month. The latter was pretty comfortable.

None of these are remotely comparable to what is being proposed for a guy who hadn't been on a bike until a few weeks ago. Of course it is possible. But the chances of injury or illness seem to me to be very high. With so short a period of training, what are the chances of him avoiding tendinitis, or severe saddlesores, or coming down with some virus because his immune system is compromised, or some combination of all of these? Just the strain on one's digestive system of undertaking something like this, virtually from scratch, is likely to be problematic.

I'd strongly advise against this. The Tour de France is only half this distance, for chrissake.