Board Thread:Theories and Speculation/@comment-28323245-20160902000709/@comment-734582-20160902085128

Considering the clones and time involved, the equivalent of some 3 years of non-stop training. (a week + couple hundred clones)

Since other elements seem even more difficult if they're not your affinity and Naruto already used Wind Release very little, my guess it could easily take months, and perhaps he can never do it.