My paternal grandmother is dying of cancer (not brain cancer). She is still relatively healthy, and is taking chemo, but there is little hope of remission (and even if that does happen, she'll probably die of heart failure fairly soon). Her current plan is to be cremated and have the ashes buried in a graveyard (in my opinion, the worst of both of the "standard" approaches, but that's not the point of this post).

I would prefer if she were cryopreserved, but am unsure how to even begin to broach the subject. I also have no idea how to convince her. She is not particularly religious, but is concerned with leaving as much money for my grandfather (and later my parents and me) as possible. I have previously discussed cryonics with my parents; my father brushed off the idea and my mom looked into it but dismissed the idea because the future isn't likely to want her (I find this argument ridiculous on several grounds). This means that I can't count on them to help talk to my grandmother. I may be able to talk to my grandfather first, but this would probably not be much of an asset: he is into several different conspiracy theories (the most recent ones center around the world secretly being controlled by the "elites" who use the U.S. President, U.K. Prime Minister, etc. as figurative puppets), but my grandmother doesn't seem to believe these and probably wouldn't listen much to his talk of cryonics either.

Any suggestions of how to broach the topic or convince her once the topic is broached would be appreciated. I am currently at my grandparents' house, but am leaving less than a day after posting this (most of which will be spent at the local nighttime, and thus asleep). I would prefer not to upset her, both for obvious reasons and because I may not be able to bring myself to bring it up on the day we depart if it will cause us to leave on a bad note.