I find the idea of pilgrimage intriguing, especially as the Ridgeway is used in many other ways. The practicalities of walking a long distance either on one's own or with a group has to be broken down though. Camping along the way, could cause litter, availability of food and water is sparse as has been pointed out, so are we talking about organised groups, who can meet up with a land rover at specific points or even a coach, or (my preferred option) could we take a pack horse ;).
Pilgrimage would be to the prehistoric sites I suppose, and the guide book would give a practical outline of their histories and the good thing about The Ridgeway is you would'nt get lost.......