Interesting, Mikey, ^^
You ate a bit more than I thought. In particular, you clearly have a taste for strong (energy) drink when riding!
The only time I've ever really run out of energy was at the end of PBP when, after eating well the whole way, I got it into my head that I could manage the last 300km on three or four croissants.
I've done a little bit of research into this recently in the context of preparing for the 24 hour TT. I ran out of fuel on that last year, although not as badly as PBP, but ended up spending quite a few hours plodding along at 12mph.
My research has thrown up the figure of 300 calories per hour as being what a typical person can take in on endurance events, and I was aiming for that on Saturday. Of course you need to use your own reserves as well. At some point, you would run out of reserves but your ride suggests that there is more margin of error than I had assumed. It sounds like you certainly finished with glycogen still in your legs.
Anyway, apologies all, this is a bit OT but interesting for me!
And ditto to comments about great photos! Thanks for posting.