I'm familiar with Pascal's wager. Is mugging just its application for manipulative purposes?
For me, the convincing counter to Pascal is the recognition of an infinity of third possible explanations. No reason to subscribe to one possible God in mindspace than another in the face of no evidence.
But this situation is different. That counter doesn't work, and no others have come immediately to my mind. Do you know of one?
Pascal's mugging. You are doing a similar thing to yourself: focusing on one possible scary outcome to the neglect of other, equally probable ones. E.g. eternal bliss, creating multiple clones of yourself, all enjoying eternal happy life beyond your wildest dreams. The odds are tiny and unknown, but both risks and rewards are potentially huge. You have no frame of reference, no intuition and no brain capacity to make a rational choice in this case. So don't bother.
http://www.theatlantic.com/technology/archive/2015/05/immortal-but-damned-to-hell-on-earth/394160/
With such long periods of time in play (if we succeed), the improbable hellish scenarios which might befall us become increasingly probable.
With the probability of death never quite reaching 0, despite advanced science, death might yet be inevitable.
But the same applies also to a hellish life in the meanwhile. And the longer the life, the more likely the survivors will envy the dead. Is there any safety in this universe? What's the best we can do?