Thanks.
So, 850 miles over 7 days, through a series of checkpoints.
What are the arrangements for sleeping and can you book hotels etc?
You can book hotels
There are usually very basic sleeping arrangements at the "Controls" or checkpoints. There is a control approx every 100km
When I did it in 2005, I slept on the floor in a village hall (bad), on the floor in a village hall (good), in a YHA (v good), another YHA(also v good)
The first sleep stop can be a problem as a large proportion of the entire field of 500 riders tend to end up at the same small village hall
The time limit is 116h which includes sleep
If I did it again I would probably book a hotel for night one near where I was going to get to for that night.
Also I'd probably get a few people of a similar speed to ride with