They seem pretty well advanced, which is reassuring. They're starting the optimization / bug fixing / localization, according to Tobi, which implies most of the content is in there. Of course, optimization and bug fixing are relatively unpredictable in nature.
 
Not surprising given production quietly started after finishing the first game.

So that means it's been development for six maybe seven years already.

As for bugfuxing and optimization yeah it's a pain. Just read the posts from the developer about how each patch fixed the game, and ended up breaking it as well.
 
They're also obviously a lot more familiar with the engine now compared to when they were developing KCD 1, so I'm sure that helps.