I just re-watched this, and I realized something: Charlie became the new owner of the factory, right? His whole family got moved in?
It seems pretty unavoidable, as far as I see it, that he would have gone insane, just to fit himself into the niche he was filling. And his whole family had to have died within the first year, with all those deathtraps! Either that, or the Umpa Lumpas psychoanalyzed them in song until each and every one of them went insane as well.
Could there really have been a happy ending here?