I got a very short window of opportunity to update my dead projects to the latest NodeJS and Angular and I just checked that Angular 6 is now available. My portfolio site, which was built on Angular 4.4 has been upgraded pretty smooth. However, I have a big old dead project written in Angular 5 and I still have to see if I can upgrade easily.
Good thing is that they provide a tool to help developers upgrade their applications.
See this Angular Update guide.
Good luck to me and to all developers who still cares about Angular :D.