After all that angst, it seems to have gone rather well.

Over 20 people came and I'd catered just about the right amount of drink.

People were pretty complimentary and I don't think it was just politeness (or the wine!). In fact one self-admittedly cynical colleague said that he was sceptical of the whole idea and was actually surprised by it being better than he'd thought it would be.

So I guess the moral of the story is to be bold and go for it!