Hi Dave (Again)
Travelling home from Ile de Re we went via Le Mans Rouen. I've just had a look at my satnav and atlas. If you travelled via Nantes and Rennes you could pick up the TOLL FREE A84 on the northern outskirts of Renne. The A84 is an excellent road. We travelled the A84 both ways from Calais to Brittany last year.
If you do take the A84 I would STRONGLY recommend the municipal at Pont Farcy which is less than 10 minutes from Junction 39 of the A84. We stayed at that campsite as a night halt on our out and return journey last year. Although it is close to the autoroute it is hard to believe how quiet and peaceful it is. You can read my review here:
http://www.ukcampsite.co.uk/sites/reviews.asp?revid=9873
According to my satnav it is 193 miles from Les Epesses to Pont Farcy.
If on the other hand you decide to travel via Le Mans and Rouen another possible near to the A28, which we used in 2008, is Camping St-Nicolas. You can read my review and see my photos in my French Pyrenees Holiday here:
http://www.caravantalk.co.uk/caravan-holidays/journals/europe/french-pyrenees-part-2
There are more of my photos of the site and village here:
https://www.dropbox.com/gallery/63718686/1/French%20Pyrenees?h=5dd0da - the relevant photos are in sub folder Py Pt 2 - Le Bec Hellouin
I hope this helps.
Best wishes
Tim