Well, I just sat down with a cup of coffee this afternoon, looked at Steve's tracker, and saw he was at the end of the road - about 1/4 mile away.
I quickly changed into cycling gear, got the fast bike out, and set off in pursuit.
It took me about 4 miles to catch him on the A10, and we turned off onto a quieter road so we could have a chat.
He's hoping that by going easy for a while, he will recover and be able to develop more power. We U turned at around 95 miles for Steve, and retraced the route. He will aim to take a slightly longer homeward route, but thinks he will end up with a 'short' (210mile) day!
I think it cheered him up lots having someone to ride with.