I suggested to my daughter (the one who isn’t engaged but planning planning planning) that instead of saying that they are inviting only siblings or only uncles that they might agree that each side gets 12 relatives or 20 or whatever they want. The groom has 2 brothers, parents, grandparents and 9 million cousins. Bride has a mother (me) a sister, and one grandmother still living who cannot travel, so place of the wedding will dictate her attendance.
I think it will be decided by having a wedding and at least one separate reception on the east coast.