Blatant plug: my only-slightly-derivative Oxford-London overnighter is on 16 October. Compared to the FNRttC:
1) it's a little bit longer (67 miles)
2) there are three psychotic hills (Chinnor Hill, the legendary Smalldean Lane, Cryers Hill and three that just make you grunt a bit; Horspath, Welders Lane and the climb from the canal up to Harefield)
3) it's incredibly cheap...about £4 train fare to Oxford
4) you get home earlier if you live in London
5) Road-runner is the Tourist Tony of the west and does 3am refreshments and YACF access
6) some of the later lanes are tricky because of potholes and loose gravel; it's not ideal for huge groups
7) there is no moon, or just a little sliver of one
8 ) very little of it is built-up, except the run into London through Ruislip and Ealing
9) you get to do the Chiltern Hills the *hard* way
10) breakfast is totally unplanned, because there's always somewhere open.
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