I second Newcastle / Northumberland. If you look around the very edges of the city, you can find places that are quite quiet, BUT that also have direct metro access into the city centre.
You could find a nice sized older house, and ideally it would be backed with countryside, suitable for your cat.
I am not a Geordie, but really like Newcastle. LOTS to do (usually) and only a 20 minute drive to beautiful beaches and countryside too. I spent all of lockdown alone on a beach last year. Well, me and GS.
I've got another 'keen'... Ouch!
What is a reasonable minimum spend for an online grocery delivery??