Oh ok… I was under the impression that those were his parents’ siblings. Do his parents have siblings located over there that they can invite? Maybe he wanted to include the distant relatives because his parents’ siblings don’t live there and those are the next blood relatives? I think it’s fair to keep the guest list to very close friends, grandparent, parents’ siblings, and 1st cousins. I wouldn’t get offended if I wasn’t invited to a 2nd cousin’s engagement party because chances are, I’ve never even met that 2nd cousin.
If that’s what you finally decided and you’re happy with it, then :k: 
You can still have an engagment party at your house, have decorations, nice clothes/jewelry, and pictures to make it meaningful. Then have a get together with friends to celebrate.