Hi dhutch2501 from a fellow "sandgroper" that is totally addicted to narrowboating. I have never done any singlehanding and I am not sure that I would be brave enough, even at 59 let alone 75, to tackle your planned trip for your first attempt on the cut. There is an old saying that less is more and I know that when you travel as far as we do to take on the canals, you feel that you need to do as much as possible. Experience tells us that slowing down and smelling the roses is so much better. We for instance in 2012 left from Mercia Marina in Willington and did the Cheshire Ring in two weeks with a total of 10 people(8 Aussies) on two boats. My wife and I are doing the Cheshire Ring from just off the ring at Venetian Marina from the 9th of May until 23rd of May this year because we felt that we didn't give ourselves enough time in 2012 to do justice to it.
Take your time and enjoy the whole experience.