Following on from day 16, day 17 continues in Matthew with verses 36-51. Again the verses look very much end times, and of course have an obvious application to those days. But if the coming of the Son of Man is to God in the previous passage, then the coming here must also be that - though coming to God in heaven is followed by a return to Earth (note there's some assumptions here in terms of the nature of the resurrection - Christ comes back to Earth to stay with us, not to take us back to heaven with him).
In essence then, Jesus is saying that while he is taking on the establishment, only the Father knows the exact nature of the events (verse 36). All talk of one being taken and another left is not some rapture to a Platonic realm of clouds and harps, but when the angels come to gather the elect, i.e. when they accept the gospel.
Much of this hinges on thinking what the household is. House can also refer to temple, and given this whole passage begins with the disciples musing about the Jerusalem temple, it makes sense that the wicked slave is the temple leadership, and that Jesus resurrection is a judgement on them because they are rejected and end up weeping and gnashing their teeth.
The advantage of all of this is that it places Jesus firmly in the first century as a Jewish prophet, who understood himself as Israel's king. Again, his claim 'to be God' is tied up in his understanding as the replacement of the temple.
So do we loose anything in seeing all of this as attached to the ascension? Surely not, for it fills the everyday sharing of the gospel with its proper cosmic and end times significance. Paul picks up on this theology of return in 1 Thessalonians 4, so none of this is dead history. It is just that Jesus was a Jew speaking to Jews, and was concerned firstly with them. They were God's people, and he was both their king and their God. To read the text that way does not mean we miss out, but simply that we are reading Jesus as he is meant to be understood. We can then move on with Paul into Jesus' return to earth.
We too then are to keep awake, not so we can spend all of our time wondering when Jesus will return, but to live faithfully until he does. We certainly don't want to be like the political collaborators of the temple, making life hard for all under crippling debt or a corrupt religious institution or dead religion. Our faith is to be living and active less we are found to be hypocrites.