An SR22 can do EGNH - LFML nonstop.
Your bladder never ceases to amaze me. I would have stopped at least twice on the way back from Croatia.
My route is likely to be direct from Dieppe (where I will land and clear customs) and then direct to Marseilles with one stop en-route.
Dieppe seems like a strange first stop, because you've thengot Paris directly between Dieppe and Marseilles. Have you got another reason for choosing it? If crossing the wide part of the Channel, how about Caen and then west of Paris? Or if you want to go east of Paris, there's Le Touquet, Lille, Troyes, Lyon-Bron.