This is extremely difficult for the Eterbase team. It's already gone, it will only be back if the hacker will decide to give it back, lol (extremely impossible).
Using such a mixer for this hack is kinda impossible, it's really huge amount of Bitcoin, I also don't know what the hacker will do. The address for sure used in the hack is already flagged in some exchanges or other services.
They moved some to Binance and exchanges are working together these days to combat hackers. And since they moved the cryptos to exchanges, Etherbase might actually might get those funds back
https://i.imgur.com/Dh7pCG4.png