What time period does the consummation cover?
The consummation covers the entire span from eternity past, when creation was first called into being, through the thousand-year reign of Christ, and into the new eternal state of a new heaven and new earth. It encompasses everything from the beginning until the final transition into that eternal state, when God is consummate.
Les explains that after the thousand years of Christ's absolute rule as King of Kings are fulfilled, He will give everything up to the Triune God. That will be the consummation of the whole—everything from eternity past when creation was called into being until the new eternal state: new heaven, new earth, new everything, untouched by Satan or defilement. At that point God will be consummate, and even the Lord Jesus will be under the power of the Godhead.
And when all things shall be subdued unto him, then shall the Son also himself be subject unto him that put all things under him, that God may be all in all.