I think from what you've said, your responses and your positive and realistic attitude GBP10,000 per year will be plenty (No major city) Just be sure your leccy is controlled, and not too many family 'treats'.
As Tawi2 says, important to be sure your UK unavoidable expenses are covered.
Remember your medical expenses if emergency. NHS will be limited.
Take care. Very best wishes. Good luck.
Any further questions fire away. If I can help you in any way I will do so. Just PM me
God Bless all there