Why do we never do a pre-season in Northern France?

Easy to get to for teams and fans an lots of reasonable teams in the area.

Nantes, Rennes, Brest, Angers currently in Ligue 1, Caen, Le Mans, Lorient, Le Havre all in Ligue 2.

Just seems a reasonable area to go for a summer camp, play a few reasonable teams at little cost.