I am afraid now we can consider cryptopia case as lost
There is a list of stolen cryptocurrencies (with amounts)  https://github.com/elementus-io/cryptopia-hack/blob/master/README.md
It is about $16M USD overalll and with current market condition I cannot be optimistic

If the cryptopia hacker can't spend the stolen funds maybe cryptopia could offer the hacker 10 pct of the total too return it i don't know how something like that would work but it's worth a try I'm sure cryptopia users be way happier too lose maybe 10 pct and get there accounts back if possible just a thought I'm sure it's pretty hard too execute a plan like that but desperate times. Desperate measures