We had our topping-out ceremony last Thursday. However, due to the schedule, the roof was already covered. Planned start was 6 p.m., the craftsmen left at 10 p.m., and we only got home at 1:30 a.m. We had expected up to 40 people, but usually many come unannounced or do not respond to "invitations."
We skipped meatloaf because the craftsmen get that every day (e.g., also handed out by us). So we ordered a stuffed pork roast from the local butcher, which cost around €350 for 40 people including drinks.
The tree was a retired small spruce from the nearest tree nursery, decorated with ribbons and tissues.
It was a nice occasion. What you have to keep in mind: depending on the season, definitely pay attention to lighting. We had additionally purchased extra floodlights to be able to guide the group through the house. I consider heating lamps overrated since it is just a shell construction.