It’s a beautiful day for it. The sun bounces off the white squares of the picnic cloth which runs from the Arc de Triomphe to Avenue George V. Traffic lights are still turning from red to green, conducting no one. Elodie and her partner are among 4,000 lucky ticket-holders to the free grand pique-nique des Champs-Élysées held on 26 May. They’re enjoying the novelty of relaxing on the road that they usually cycle down for work, dodging cars and selfie-absorbed tourists. “We are Parisian, and this is a place we have been driven out of,” says the 51-year-old writer. “It’s not a museum, not Emily …