Ah, the torture and blessings of wine!
First, I'd say the primo thing to do is fill up on healthy stuff BEFORE you go! Especially bulky stuff with plenty of fiber to keep you full. This way you won't be as tempted to go nuts on the spread in front of you.
Another thing you will need to be careful of is your self-control once you drink the wine, well, that is, if you are actually drinking and not just spitting it out
For myself (and most other people I think!) once I have a drink, my firm rules start to get blurred, then can be tossed to the wind... with me thinking stuff like "Oh what the heck... life is short... live it up for tonight! Diet tomorrow!"
Helps to keep in mind the future is now
Self-indulgence can be justified over and over for a long time and losing weight becomes an impossible goal in the imaginary future. I'm talking to myself here as much as you
With the foods you mentioned, I guess I'd try to stay away from the fondue if you are on WW. WW is a low-fat diet and fondue could really kill your Points for the day.
Be mentally prepared to gain the next day with the salt you will be having... even if you are pretty much on track Points-wise, there is sure to be way a lot of sodium in all of that stuff. Of course the salt makes the wine even more tempting as you get thirsty
Good luck! You can do this! Learning how to negotiate "real life" while losing weight is key; you're absolutely right that it must be done... just keep your WW focus front and center when you are there.