Invite Wording: Destination Wedding + At Home Party

You're going to want to do two separate invitations. One invitation to the Italy wedding and one for the party at home. Otherwise, you are explicitly telling people who are only invited to the party that they are not being invited to the ceremony in Italy (even though others are), which is rude.

Don't have a double one. For people who are invited to both, send one invitation for Italy and then send them the same party invitation everyone else is getting. So for your parents (for example) you would send an invitation for the Italy event and then a separate invitation for the party. For you coworker (again as an example) you would send just the party invitation.

Also, you won't send invitations until 6-8 weeks (10 weeks *max*) ahead of time. Instead, you'll send save the dates (which can be an e-mail or phone call) 10-12 months ahead of time to the guests you definitely want to come to either or both event(s) - but remember that if you send a save the date, that person must get an invitation.