I overprepared for my first herofete by a great deal. I didn't know what to expect as far as food consumption so I made seventy platters. I was able to do three more herofetes with the leftovers. 
While trying to get rid of those leftovers I gathered some information that maybe someone else will find useful when they're preparing to do a herofete.
I forgot to mention something quirky about the number of people needed to hold a herofete.
When I performed the fourth herofete I still had the effects from the third herofete as active defenses. There were nine people in the room not counting myself but I figured I'd try doing the fete just to see what would happen and it worked just fine. Apparently the cook can count as the tenth person even if they've already been in a fete recently.
While trying to get rid of those leftovers I gathered some information that maybe someone else will find useful when they're preparing to do a herofete.
CODE
1st Fete:  17 people. 49 platters remaining.  21 platters consumed for an average of 1.2 per person
2nd Fete:  10 people, 35 platters remaining.  14 platters consumed for an average of 1.4 per person
3rd Fete:  12 people, 20 platters remaining.  15 platters consumed for an average of 1.2 per person
4th Fete:  10 people, 7 platters remaining.  13 platters consumed for an average of 1.3 per person
2nd Fete:  10 people, 35 platters remaining.  14 platters consumed for an average of 1.4 per person
3rd Fete:  12 people, 20 platters remaining.  15 platters consumed for an average of 1.2 per person
4th Fete:  10 people, 7 platters remaining.  13 platters consumed for an average of 1.3 per person
I forgot to mention something quirky about the number of people needed to hold a herofete.
When I performed the fourth herofete I still had the effects from the third herofete as active defenses. There were nine people in the room not counting myself but I figured I'd try doing the fete just to see what would happen and it worked just fine. Apparently the cook can count as the tenth person even if they've already been in a fete recently.
