Even if she gets all the four of them into Uta World, she'd need endless mushrooms to stay awaken for long enough to defeat them.
We don't know about Shanks' stamina, but we know he's able to duel Mihawk, defeat Loki, stop Akainu easily and one-hit the whole Kid Pirates.
BB's stamina is pretty poor, but he managed to endure huge damage many times along the series.
BM couldn't get anyone's lifespan but her own, though she's still crazily powerful and endurable. It's said that Base BM <= Base Kaidou.
As I said, Kaidou could defeat Uta on his own. He just needs to wait till she falls asleep, since Tot Musica isn't strong enough to kill him, even if he lets it hit him.