That might be classed as 'exclusive' - or Ultra-Speedy Ride... Forget the 'Night' bit and your distance would be at the edge... FNRides are a mixture of capable people who can absorb distance and exertion, riding with those who are building up either or both, or merely dipping a tentative toe in the waters of group riding. I like them because the night is a leveller of souls and an opener of eyes. Plus, there is reasonable technical 'clout' re: waymarking / repairs etc available to get by - which is reassuring to less practised riders. Ultimately, coastal rides from London can cope with total failures or bail-outs...in the wild and woolys, this might pose another problem?