Thanks everyone, I’ve really enjoyed reading the responses over the day.
I like the idea of Arnside / Silverdale / Grange-over-Sands. I’m originally from East Lancs and spent quite a bit of time walking with my Dad over that way as a boy / teenager, and I would like to return to the North (my wife might feel differently about that!). The train line is appealing – you can get to Morecambe and Lancaster and onto Manchester pretty easily for gigs and other fun.
I also know Lytham reasonably well, but I think I’d prefer around Morecambe Bay.
I’d like this to be a thread for everyone, so my suggestion to throw into the mix is Burry Port just west of Llanelli in South Wales. The beach is pretty nice, there’s the Millenium path along the coast to Pembray / Pendine sands, and a train line to Carmarthen or Cardiff one way, and Pembroke and Haverfordwest the other way. The town is a bit tired but still has pubs and convenience stores (and a good Greek restaurant), and Llanelli has loads of supermarkets and some shops left.