I'll be going on foot from Plymouth, seeing as I live there and the ferryport is only ten minutes away in a cab.
Just sling the bare esential (clothes, tent, chair, sleeping bag) in a rucksack and hop on the train from Morlaix to Le Mans. I'll be there only 4-5 hours after arriving in France.
I can buy whatever else I need when I get there.
And I won't have a long drive or train journey when I get back either. Only costs £105 for a return ticket.