Second, for 180 people you need to set up 3 serving lines or 2 double sided serving lines. Rent chafing dishes or use disposable chafing dishes for the hot food. These must have the steam pan under the food pan to be safe and effective.

Third, roasters only hold about 50 servings and you can only run one per twenty amp circuit, which often means one, or at most 2, per room. You need to plan to keep the food hot in the ovens and transfer to chafers as needed. Chafers hold about 25 servings per pan.

You have some logistical challenges here, good luck. Plan carefully.