Maybe we could stop freaking out about keeping birth rates high? "Devastating" carries a negative connotation. If the quality of life for that additional 10 years is good, I'd call it a positive. If it's 10 years hooked up to machines where your brain's working at half capacity, then yeah, that's a negative.
Well, if it turns out to be such a big problem, then we can just kill everyone at a specific age.
That's sarcasm, of course, but IMHO saying that we shouldn't prolong life because of possible consequence X is morally exactly equal to saying that we should kill old people to avoid that consequence X.
For every X, either X really is so bad that it's worth killing people for it; or X shouldn't be considered as a valid argument against longevity.
Could you give an example of how to be proactive as such? I agree that being prepared is good, but I don't personally know enough about old-age care / geriatrics / Social Security to really be in favor of or against any particular policy changes.