Thanks for the additional ideas.
Looking on Google maps there isn't a great deal of difference in mileage or time whichever route I take. Even going west from Derby to the M40 then the M25 anti clockwise is only 15 mins and about 15 miles difference but it's more time on the M25!!
I'm thinking M1, A14, M11, M25 & M20. That way we'll have less time on the M25 which from experience is or can be bloody awful! We'll have to make a decision on the time we make the rides down & back.
Joe, we don't enjoy motorways at all, but this trip is about time spent in Normandy around the WW2 beaches, museums & cemeteries and the sooner we get there the more time we'll have for that.
TLP, I'm hoping to have enough visits to Derbyshire cafes by the end of June to keep my body sustained through nine days of eating Croissants, Coq au vin & Escargots.