Interesting city could be significant. If you have friends and family spread out then decent transport links could also be a plus.
The south west in my experience was fairly free of sprightly civilisation but then I was in Bridgwater. Further north towards Bristol could work and you’d have sensible train/motorway and airport links. THe SW is warmer than a lot of the rest of the UK. Accomodation seemed expensive.
I now live in Newcastle, colder than anywhere else I’ve lived. It is very noticeable although you get used to it. I don’t own many shorts these days although I did have bare knees on my ride today. Good transport North and south with trains and planes. Roads aren’t too bad. House prices are cheap.
I also lived in Bolton in the NW, but I see no reason ever to go back there.
I’d look at South of Manchester. Somewhere in and around Leeds/Sheffield or Edinburgh.