anyway, some background

The Soyuz capsule currently linked to the ISS, and the one the crew must use as their return ship, has a "use by date" in January / February 2019. As I understand it, the Soyuz capsule is only certified for six months continuous vacuum exposure.

So, the crew can come back anytime, and must come back by early February. If there hasn't been a new capsule launch by then, they will leave the ISS empty / uncrewed, and it's not really designed for that.

My understanding is not that the crew is marooned, but that there is a risk that an untended ISS might either deteriorate or get damaged to a point that it would be unsafe to reoccupy, or its orbit might decay and it re-enter uncontrolled

My $0.02

ah thanks

And The Register says

https://www.theregister.co.uk/2018/10/11/soyuz_nasa_international_space_station/

Don't worry - there's Commander Alex aboard. You could ask him what's next: https://www.facebook.com/ESAAlexGerst/

New team has arrived recently, former ISS team will be back Dec, 20th.

It's all because that bloody Hal won't open the Pod Bay door.