Board Thread:Theories and Speculation/@comment-33953813-20180114191320/@comment-734582-20180114192033

Kurama gathered enough Nature Energy to counter the attack. There's no real hard rule on the exact nature energy : Chakra ratio necessary for senjutsu, and as long as you can suppress the side-effects of nature energy you could make the ratio as big as you like.

In essence, there's no reason to believe you couldn't gather 10x your own chakra as nature energy. Or 100x. or 1000x.