Ok, there is a high speed to Cherbroug from Portsmouth, based on a car and 2 passengers, its a 3hrs crossing, which is great, goes out at 9am on the Tuesday and gets in at 13.00 (£119) local time, returning on the Monday (£165) at 17.00 getting in at 19.00 local time.
Now, as time goes on, this price will rise, especially as it gets closer to Le Mans but at £284/£142 per person, its very reasonably and will save about £125 in fuel to go Dover/Calais.
Also, I am sure if I talk to them and get a group booking of 10 cars, I can get that price down to the £250 mark.
It will also knock 400 miles off the journey each way which will stop us from getting so knackered next year.
Stay in Cherbourg maybe Saint Vaast the first night, then down to Bernay for the second night
Or Bernay the first night (2hrs drive) then Mayenne the second (2hrs)