I did a party for my FIL's 80th and 85th at our home. The guest lists were 30-40 people each time. The first one was finger foods, snacks and such and for the second I did Lasagna, salad and bread. Honestly, the full meal (served buffet style) was much easier and less expensive. I spent part of one weekend on the sauce in three crockpots and froze it, then the day before the party had a cousin come help me construct 7 Lasagnas in disposable aluminum pans. I have a wonderful recipe that I would be glad to share with you.
Since I only have one oven, I baked them in the oven, a couple at a time then kept them warm in the oven and in a couple of large electric roasters. They cut easier and stay together better if allowed to cool at room temp for awhile. The Lasagnas could also be constructed and frozen in the pans. Either way they were delicious and a big hit. Simple and inexpensive decoration of the serving table is always nice.