What is the life and death of Sirius the star?

Sirius's fate might be peaceful; just ejecting it's outer red giant layers to make a planetary nebula. It is 2.02 times the mass of the Sun. However, Sirius has a white dwarf companion. On Sirius B's death, Sirius A might have formed. At the other end, Sirius B might destroy Sirius A. White dwarfs have very strong gravity, and if it is close enough, Sirius B might steal material from Sirius A. When a white dwarf stealing mass from the parent star has enough mass to create iron, the iron triggers a Type 1a supernova. If this happens to Sirius B, Sirius A could either be destroyed by the immense force of the explosion, or become a runaway star, travelling faster than even Barnard's Star. If this is the case, Sirius A might eat smaller stars or crash and burn into a larger star. If it heads towards us if this happens, we would be doomed.