Gamlingay is a feeding station only on the way out and a full control on the return journey.
cf Mortagne.
If Thurlby is the first 'control', and it's at 150km, that's 12.5hrs - this AUK would struggle to get a decent kip and still make that. (although I'm sure someone could manage it, flat out).
I guess that makes Lincoln 220km/18.4hrs the first feasible 'proper' sleep stop, and only for us late starters. Thorne is at 25hrs.
8am starters will have a much wider range of options.
EDIT: OK, I'll chance my arm and start drafting a schedule ....
2pm start. Assuming I ride at 'normal' day ride speed,
Lincoln at 220km is about 14hrs. That's 4am for me. So I'm happy to aim for there and sleep for an hour (after big nosh).
So depart 6am, that's 2hrs in the bank (hopefully I'll arrive earlier and get more sleep ... ).
Alston 526 km is a nice 300, closes at 10am
EskdaleMuir* 812 a hilly 290, closes at 9:35am
Thorne 1096 so a short 284, closes at 9:30am maybe aim to leave early
Gamlingay 1330, so 234km 4.50am - last day, probably leave on the limit!
End 64km 10am -ish
This schedule has me leaving each sleep control well after dawn, not ideal. So hopefully I'll stay far enough ahead of schedule to get a good kip and still leave around dawn. On the plus side, I hate getting up in the dark, so I'm glad I'll avoid that.
*If I've read things correctly, in 2009 this control will be replaced by one either side of it. Which is good, as it will reduce the long 115km leg to Edinburgh. But bad as I can't plan my stops.
p.s. we should probably put all this stuff in another thread some time! EDIT: nice one Mal.