Still gathering my thoughts before I try and write any of it up.
The major stat is that I had a sum total of 58h on the/any bike in the whole of 2016 before starting this ride (this includes commuting!) Only 766 miles. My only Audax in 2016 was a single 200. Hardly great prep.
I've also never finished a 400km Audax in less than 24 hours, and have never completed a 600km Audax in anything under 39 hours (and the most sleep I've had on a 600 is 15 minutes so it's not as if I was lounging around).
So I'm very happy with clocking up 292.39 miles with only 19h50 moving time. Goes to show what sheer bloody-mindedness and grim determination can do.
No energy drink (hadn't trained on it, hadn't really trained, and didn't want to risk it on the day); just bidons of Robinson's lemon squash and electrolyte tablets, a few gels and food from petrol stations, the chippy and one hotdog from the Espley feed.
Will definitely be back for another go, but a little better prepared. Probably still unsupported (at least throughout the night when small people need to sleep). Maybe not 2017 but the year after for sure.
I reckon I can put at least another 108+ miles on with better prep, more aero bike/wheels, improved fitness, consistent use of aerobars, and feeding on the bike to keep time off the bike to under an hour.