OK, if that's the case, I could probably wear the same dress to both weddings.

I'm going to buy some new heels and clutch and I have a black wrap I could wear.

To be honest, I'd rather be a bit underdressed and blend than be over dressed and stand out.
Trust me it's better to be **over dressed** than under dressed especially at a Wedding, and especially at an Italian Wedding

wear what you mentioned - your dress sound lovely, with new heels & nice clutch, definitely a wrap or nice coat ... and some really nice jewellery

... and if you ever at any point feel over dressed you can always strip the jewellery off and pop them into your clutch bag

(another tip, try not to show any bra straps !!)