The crucial thing is to let it rest after cooking, rocky.....alufoil over it, teatowel on top and leave for an hour at that size..........
Depending on your numbers, (and your oven size) knock off the legs and the crown perhaps - roast the crown and one leg of you have dark meat fans (my fav)....the rest of the carcass, do not discard as you can use the meat for a roast, curry, risottos, whatever........