There's always tomorrow. If you let them in tonight you can always block it with plywood tomorrow.They never go in it during the day.
They are out and about in the Chicken Palace, in the yard. Then they file in there at night. I was worried because it is more enclosed space than the rest of the Palace - it is inside the Palace but has a roof inside so other chickens wouldn't roost on top of the brooder.
So I was worried about it getting hot and not great ventilation. It is fine for one adult as a sick bay, or a bunch of littles, but it is getting really cramped with these 5 big ones.
I should have just left them to figure it out for themselves. I think I really stressed them (and me!).