Where I grew up (Cheshire/Derbyshire border), thou and thee were in common usage, and I both heard and used them frequently, but as both parents were teachers, it was definitely frowned upon at home. I moved away 35 years ago and very rarely meet anyone who uses them now. As Malcolm says for Sheffield (only 40 miles away), thou was usually pronounced 'tha', and thy was 'thi' as was unstressed thee.
Joe, you're right about 'you' being used as a formal singular, but my point was that English has never had a separate form to denote formal address only, unlike German, Spanish, and the Scandinavian languages. Du is singular (informal), Ihr is plural (informal), and Sie is singular or plural (formal). I seem to remember that at one time German also used Er as a formal singular!