An extrapolation from the one-electron-universe hypothesis is that the entire universe exists within a single point - this is why constants are constant across the universe, why matter is the same everywhere, why particles share properties, how tunnelling works, etc. - we just perceive it as being uncompacted from our reference frame, whatever or wherever that may be. Elements of some SUSY theories touch on this too - that there is only one string, that the universe is a projection from higher dimensions "curled up" in a planck-scale point....
Frankly, we can't know, and I'm not sure that we ever really can, due to the limitations of our faculties, and the rooting of our "reality" in how this particular collection of molecular machinery interacts with other physicality around it.