I’d also recommend the area north of derby, living in belper is lovely. Quite easy to get to various cities/towns to work if you’re looking for office jobs as opposed to freelance stuff.
Downside is that you’re pretty much furthest from the sea you can be in the uk, if by water sports you mean big boats/yachts, surfing or anything like that.
Also, as a co owner of a small child myself, I’d recommend that if you’re wanting free childcare off grandparents, you move to really quite close to them – it’s going to be a lot more of a realistic expectation if they are less than half an hour away than if they’re two or three hours away, where you’re only likely to get help if they come and stay, not a solution for times when you unexpectedly need help, or for saving money on regular childcare if you have retired grand parents.