I know this will sound a little rowdy and that is what you were trying to avoid. But with some guidance, I think it might be a little helpful with the dark, rainy night behavior that is about to drive you insane.
Move some furniture around to clear a large area. Make a 4 square section in the middle of the open area. Use a balloon or some other light weight ball to play 4 square.
This is very similar to the 1st idea. Except put a long string across the floor or tape it to the wall to play "volleyball". Use a balloon instead of a volleyball.
My boys have played alot of 4 square in the living room.
Another thing is basketball. Basketball is not good for rainy nights, but if they have a light to play by, it can occupy them even when it gets dark early. Knockout, Around the World, and Pig are some of the games to play with only a couple people.