What is the religious ruling regarding choosing between migrating to America and performing Hajj with family (knowing that the wife and sister have not performed Hajj before, and the parents are elderly and cannot go for Hajj without the questioner), if the two opportunities conflict at the same time?

It is more befitting to perform Hajj with family for several reasons, among them: realizing the benefit of Hajj for the family and gaining the pleasure of one's parents. Residing in lands where abominations are widespread is a means to many corruptions, and Allah's earth is vast. In Muslim lands, there are bounties that suffice, making travel abroad unnecessary.