I think my order of preferences would be:
CEV(myself and people like me) > hedonium >(?) CEV(humanity) > extinction of life > hypothetical dystopian space colonization with more suffering than happiness
I currently lean toward total utilitarianism, but I also care about what my idealized self values; if I would value something other than happiness/not-suffering on reflection, then I would prefer that. I don't think all humans would necessarily converge on the same values, and many current humans have very different values from mine, so I would probably prefer hedonium over the CEV humanity (assuming that's even a meaningful concept).
Then again, if hedonium just consists of the same maximally blissful experience over and over, I'm uncertain whether that is really much more valuable than just having that experience exist a few times. There may be diminishing marginal utility to each additional hedonium-unit. If I had to guess, I still think having more of that maximally-blissful experience is better.