I'm trying to find out how short-term or long-term your thinking is. Moving to Mars seems very fragile, depending on constant input from planet earth. The challenges of moving to another star system where you could have a self-sustaining life are immense. Neither option is available in your lifetime. I think quantitative estimates of the survival of sapience on earth are pretty much useless -- the uncertainties of individual estimates are way too high. As a young man in 1981 I debated moving from the US to Australia as a hedge against nuclear war, a much more modest proposition. I decided not to, partly because I could be a more effective activist against nuclear war in a superpower that was my native culture. So if you go down this path, you could think of your utility in terms of preventing the destruction of sapience on earth.