I’m surprised no-one has pointed out that the Four Counties and Llangollen options aren’t available to you, because of the breach on the Middlewich Arm.
The Caldon is one of my favourites, and it gets better the further you go. Lots of locks to get there, so if you want an energetic week this could be a good option.
I’m sure Anderton are fine about their boats going onto the Weaver. It’s lovely down there, and of course you get the trip down and up the boat lift. As others have said you could combine this with a trip into Manchester. There would be lots of lock free miles, so it depends whether your crew are happy to sit and watch the world go by, or whether they’d like more to do.