How about Sheffield....
1) While we still can - closing in a couple of years.
2) Pretty much in the centre of the country.
3) Easy to find - follow the M1 or M18.
4) Excellent cafe - fantastic choice of fillings for sandwiches, ciabattas, etc
5) Lots of room for the hundreds of ppruners who'll arrive.
6) I believe there are interesting things to see...if you don't spend too long eating and drinking, as we did.