Zurich - Christmas dinner venue

Ok so I know we've left it waaay too late, but I'm looking for a nice, but fairly informal (erm...I'm going to use the term "hipster"....) place for a work's Christmas do (30-35 people) on Friday 8. December. Ideally (and I know this *might* not all be possible... ):

- Hardbrücke/Wipkingen/Altstetten side of town

- a private room

- nice food

- not too expensive

Does anyone have any wonderful ideas of places that I might not have thought of yet/might not be booked out.

Thank you