I've already seen spoilers for the game so no worrie there. I am playing through bloodborne and enjoying the DLC, I have consumed 4 third umbilical cords. The doll has told me to go visit the base of the great tree. I have not finished all the DLC however I would prefer not to be too overleveled (if that's even possible for a From Software game) for endgame.
At what point is the point of no return and I'll be forced into NG++? Am I locked into fighting the final boss(es) after I certain or can I muck about (in the DLC, main game, etc) all I want until beating the last one?