Whether there is transmigration or not has no bearing on the living entity strictly speaking. The process is really nature's mechanism to propagate while accommodating the life force's implicated instinctual drive or desires for material inoculation. 

The living entity can and will maintain its subtle existence so long as there is a subtle support system of the world or reality that it is existentially reliant upon. So in a way, a material body is simply icing on the cake, and nature perpetually creates opportunities, within unlimited possibilities.