As a wine lover with an active imagination, I’d always pictured the French wine harvest as a cross between “Sideways” and “I Love Lucy,” a sun-drenched bacchanal featuring boozy lunches en plein air, rosy-cheeked peasants crushing fruit with their bare feet, and a bit of insouciant grape picking. But on my first morning of a week spent working in a Champagne vineyard, the clouds hung low and leade