You can always get it down to zero letters! The game should remind you how many letters you have left before you can win to make it clear .

I didn't understand what you were saying at first, but it turns out that you have to click to remove the final, single letter before the "you won" screen shows.

And I agree it would be nice if the game could detect when you've reached a dead end and notify you somehow.

I think I've tried every combination herbs possible, you have to whittle to her and the to he, and then there's nothing, what do you mean?

They are saying "the win screen shows up after you click to remove the final letter", not "it is always possible"

It’s solvable if you whittle down to “a”