As if by magic, here's the
route I took in June.
I don't think you need panniers but my advice would be to stop everywhere that you can see food available or at least don't think "Oh it'll be ok there'll be another place soon". I ran out of food and water at least twice. Really, really eat a lot between Burton and Ashbourne, you will need it!
I left London at midnight cos the A5 is ok during the night. I'm not sure it's bad during the day but at night it's relatively pleasant if a bit boring. I got to my destination which was 230 miles at about 5pm but as I've mentioned I ran out of food and water which
really slowed me down.
If you need any other advice feel free to PM me.