Madara would most likely win all 3 scenarios.
In all 3 scenarios he can tame Kurama and use his Perfect Susanoo with it.
In scenario 1, Bijuus have no counter. Tanked hits from all of them, without even using Susanoo.
I don't see them breaking his Perfect Susanoo with that feat.
In scenario 2, Its more of a fight, but Madara still has the uperhand. When Naruto was fighting Obito, Half Kurama's Bijuu Bomb went againts 6 Bijuu bombs together. A full Kurama should be able to counter 8.
And lastly, scenario 3 would happen just like in the Manga.