I've thought for a while that the Kim family basically needs to be bought out by the rest of the world. One of the big problems is that most of the scenarios that improve life in NK involve the likely deaths of the leaders (or at the very least their imprisonment), which they obviously will stop at nothing to avoid.
As distasteful as it may be, they need an offramp and that probably looks like them being assured living out the rest of their lives in luxury.