In reply to Whitt:
We just got back from Burgundy (Bourgogne) in the centre of the country which was around 5.5 hours drive south of Calais. The area we stayed at was pretty remote (near Clamency), but handy for both the Morvan national park to the east and Loire valley to the west.
The road cycling is peaceful and although I didn't go off-road, I understand there's plenty to go at in the area if that's you bag.
We also squeezed in a day trip to Paris, which is about 2.5 hrs drive/train away.
FAs a final bonus, we managed to come back with around 30 bottles of excellent wine, not bad considering that alongside my wife and I, there were four teenage kids and my bike in the car.