Simply put, the "greater works" of which Jesus spoke encompass the good deeds of the saints of God worldwide. Although Jesus' works were remarkably awesome (and the apostle John insists that his gospel included only a small portion of them--see John 20:30), the "greater works" are accomplished in the power of the Spirit by the members of the church universal, which of course is spread throughout the entire world.
With very few exceptions, Jesus limited his working to the tiny country of Israel, and as far as we know he never ventured abroad with his message of the kingdom of God/heaven and repentance. He left that work, and the various signs and wonders which often accompany it, to his disciples throughout the world as they obeyed his "Great Commission":
Go therefore and make disciples of all the nations, baptizing them in the name of the Father and the Son and the Holy Spirit, teaching them to observe all that I commanded you; and lo, I am with you always, even to the end of the age (Matthew 28:19-20 NASB).
In other words, Christians since the first century have been the hands, feet, and tongue of Jesus in the world. As they obey Christ in making disciples, those disciples will in turn make disciples themselves. In so doing, the works of Christ proliferate among more and more Jesus-followers.
Lest Christians think that only the showy, spectacular, and awe-inspiring works (e.g., healings, resurrections, and other sign gifts) are the "greater" ones of which Jesus spoke, they need remind themselves of two things. First, the greatest of all works was our Lord's cross-death and resurrection. And second, our Lord made crystal clear that the primary work of his disciples on earth was making disciples, through preaching, baptizing, and teaching obedience to his commands, the greatest of which is to love one another (see John 13:35).
Some food for thought . . .. During Jesus' public ministry, including the 40 days following his resurrection, Jesus (and followers of "The Way") numbered in the thousands. In heaven, thanks to the "greater works" of Christ's body worldwide, there may well be scores of millions--or more--of Christ followers in heaven!