Make sure you have all of your shakes before you go that way you won't be so hungry & try to stick to a no/low carb meal if possible.
Jump straight back onto SS the next day and hopefully if you can stick to protein/veg or salad then you could still be in ketosis and won't have done too much damage.
The worst thing about this diet is that if you come off it for any reason - it is sssooooooooo hard to get back into it.
I've avoiding eating out by convincing people they'd rather do other things. I was at a buffet yesterday and I mingled and drank coffee and soda water.