I'd slightly misjudged the time and it was time to put my headtorch on as I reached the top of the road. All downhill to home after that though.
Once the GPS data was uploaded it became clear that I'd done a level 1km section in my second best time and up through Dore was a PB by a few seconds! None of this is meaningful but at least it showed that I wasn't 'ill', I just had a sore throat.
Many years ago I read an article suggesting that you never really know if you're really not fit to go out until you do. Many times, once you've taken the plunge it all feels OK.