Bad analogy, actually. If I have an incurable terminal illness today and fall asleep, I'll still have an incurable terminal illness in most of the worlds in which I wake up— so I should assign a very low subjective probability to finding myself cured tomorrow. (Or, more precisely, the vast majority of the configurations that contain someone with all my memories up to that point will be ones in which I'm waking up the next day with the illness.)

I'm not quite sure how it might play out subjectively at the very end of life sans cryonics; this is where the idea of quantum suicide gets weird, with one-in-way-more-than-a-million chances subjectively coming to pass. However, if I'm signed up for cryonics, and if there's a significant chance I'll be revived someday, that probability by far overwhelms those weird possibilities for continued consciousness: in the vast majority of worlds where someone has my memories up to that point, that someone will be a revived post-cryonic me. Thus I should subjectively assign a high probability to being revived.

Or so I think.