Day 7, Road swing bridge at Foxton is very heavy to open/close.
Day 8, 9, Be aware there are strict opening hours at Foxton and Watford locks, can also be long queues. Could be held up overnight at either or both! Long summit pound, is not deep, so speed will be restricted.
Day 9,10, Are you sure about going to Stoke Bruerne, it's a long way off the Leicester Ring.
All in, I feel you are expecting to have a very high average speed, leaving no time for hold ups/shopping, or even loo breaks, if single handing.
Bod.