I can help, OP. There are loads of lovely restaurants in the area, although Nuneaton itself I don’t think has much to offer in that regard.
I have an Airbnb locally, and these are the places i recommend to my guests. I don’t know if any of these are places you could hold the ceremony, but:
Barnacles on the A5 between Nuneaton and Hinckley. They have a beautiful
restaurant and a year round tent thing in the grounds and the food and atmosphere are great.
Hercules Revived, Sutton Cheney
Horse and Jockey, Congerstone
Black Horse, Market Bosworth
Softleys, Market Bosworth
San Giovanni, Sheepy Magna
Fourwards at Ashfields, Earl Shilton. Not the prettiest location but the food is really brilliant and it’s lovely inside