Well I don't know exactly what he's saying because I can't do quantum maths. The quantum 'sum of all possible paths' (possibilities) I believe actually results in the vast number of such infinite possibilities cancelling each other out. So in reality it's a mathematical probability device that in reality leaves, for instance, the electron close within its most probable atomic radius.

Although semantically it could be anywhere in the universe, mathematically it's hugely vanishingly unlikely to be anywhere else but close within the atomic radius? Or ionised, but close by? Well, I don't really know.

So the 'infinite multiverse' sounds philosophically nice, but perhaps in his old age Hawking was really concluding that although infinitely many possibilities theoretically do exist, in reality they will largely cancel each other out and leave a reality close to that created by our own 'laws of nature'?