I ate at L20 two Sundays ago. There were four of us. Each of us ordered the four-course option. We did not ask if we all had to order the same number of courses, nor did our server say one way or the other. In addition to the four courses, we ordered the beef entree a-la-carte for the table. Two of us asked the sommelier to pair wines by the glass with each course; two others ordered two wines by the glass each. Our total, including gratuity, was about $250/person.
The four courses, plus a couple of bites of the beef, provided plenty of food. It was all very good, by the way, every course and every wine pairing. The service was terrific, too. My favorite thing was the skate.
-Dan