each time we crash hugely there is a real risk that the overshoot might be so big that it actually kills bitcoin.
Really? Explain how dropping down to $2 can kill bitcoin? Wild oscillations are normal for this type of completely unregulated herd-driven market; and bitcoin's essence could never be killed by any amount of overshoots, given that there are larger periods of stability inbetween the wild rides, allowing it to be used for transacting once the new price levels have been established.
And no, I don't think it is possible for bitcoin to just freeze around the new ATH level without oscillating. That only means there's more room to go up.
If it goes to $2 now, everybody will write it off as worthless and nobody will want it any more. It currently costs about ¥1000 to buy a hardcover book. Nobody has a problem with that in Japan. But if suddenly it cost $1000 to buy a hardcover book, in the US, there would obviously be a big problem.
Declines in value are what causes people to lose faith in a currency, not how much a single unit of that currency actually buys.