I'm not going to give my initial reaction.
But, I will say I live in Europe, and traveling in Europe NEVER looks like the travel guides. There's traffic, and in Italy particularly, workers go on strike (all of the vaporetto drivers have gone on strike two out of the 4 times I've been to Venice). I realize Portofino is the opposite side of the country from Venice, and I'm not saying you can't have a beautiful wedding there, but you will hit snags...or more specifically your guests will.
We could have easily gotten married anywhere in Europe. It probably would have been MUCH easier on us. But, it was infinitely simpler for our guests to travel to Disney. And, frankly, there was far less that I had to worry about in the process.