As I understand the many worlds interpretation of QM, theres no collapse in the wavefunction just a splitting of the universe! So given that I believe theres always a possibility not to die at a certain moment, the universe splits in 2 one where im alive and one where im dead. As long as theres some tiny tiny little possibility of me surviving I will do that in some universe. And given that I die in some other I would have to presume that my soul, and I, goes along to the universe where I am alive ! I see no reason why this shouldnt go on atleast to the end of all universe's. Sure ill be old and grumpy but thats ok with me.