Law will go his own way after Wano to try to find the last Road Poneglyph with his crew, i can even see a scene of he and Luffy remebering the talk in PH about defeating Kaido. But the ones that will find it will be the SH, pehaps in Elbaf, and them the SH will go to Laftel and after that Law will rejoin with Luffy for them to go after Imu.
Is heavily implied that the Ope Ope power was the one used to make Imu immortal centuries ago, so probabily Law will be the one to give his life to defeat Imu imortality, fullfiling his destiny as a D. and dying with a smile in his face. Oda putting he as a D. show that his place in the story will be much bigger than we think before.