I was in a similar situation with invites. My dads side of the family is similar. He hasnt spoken to his one sibling, my uncle, for many many years. I wasn't sure what the proper thing would be to do. My dad was okay if we didnt invite him. That being said I didnt want to cause any unnecessary family drama by not sending them an invitation. They did get one, however, I knew they would never come in a million years so I was okay with sending them one. Do you think these people will actually show up to your wedding? If you don't think so then send them an invite anyways, at least they will feel included. Its a tough spot to be in, but you need to do what you want for your wedding and that means inviting who ever you want to!!