Swis, check out these guys at mundArtbeiz:
http://www.mundartbeiz.ch/home/
It is a restaurant featuring traditional Swiss cuisine in Rapperswil, the quality is excellent, the portions big, and the owners Andreas and Angelika are lovely people. The menu and website are in Swiss German - funny when you read it - but the owners speak English. At least, with my poor German and their good English we managed to understand each other
I would give them a call to see if they are open and if so, if they are doing special menus for New Year's Eve. I know they are doing something around Christmas for CHF 60 per person or so.
I recommend this place without hesitations, I loved their food and company. Also, you will be in Rapperswil, which is a lovely place to be - you can walk around the old town and also stroll by the lake.