We know from Revelation 20 that people aren't judged (those not saved during this life the first time) until the time after the millennium ends:
"But the rest of the dead did not live again until the thousand years were finished. This is the first resurrection . . .
"Then I saw a great white throne and Him who sat on it, from whose face the earth and the heaven fled away. And there was found no place for them. And I saw the dead, small and great, standing before God, and books were opened. And another book was opened, which is the Book of Life. And the dead were judged according to their works, by the things which were written in the books. The sea gave up the dead who were in it, and Death and Hades delivered up the dead who were in them. And they were judged, each one according to his works. Then Death and Hades were cast into the lake of fire. This is the second death. And anyone not found written in the Book of Life was cast into the lake of fire." (Revelation 20:5, 11-15)
People aren't put into hell now when they die, and then get pulled out, judged again, and then thrown back in. These texts are too unclear to really accomplish the goal they are typically used for. They are too unclear, since neither says we have an immortal soul that's conscious separately from the body. Such thoughts have to be read into the texts in question.
It's far easier to say that (in the case of Philippians 1:23) that when the apostle Paul would die, he would have no consciousness of passing time in the grave, so therefore the moment of death is followed by the moment of being resurrected and coming with Jesus at the Second Coming. Neither text says WHEN Christians enter the Lord's presence. If I said it was to occur at the Second Coming (as per 1Corinthians 15:23 and 1Thessalonians 4 below), there's nothing in either text to contradict this belief:
"For if we believe that Jesus died and rose again, even so God will bring with Him those who sleep in Jesus. For this we say to you by the word of the Lord, that we who are alive and remain until the coming of the Lord will by no means precede those who are asleep. For the Lord Himself will descend from heaven with a shout, with the voice of an archangel, and with the trumpet of God. And the dead in Christ will rise first. Then we who are alive and remain shall be caught up together with them in the clouds to meet the Lord in the air. And thus we shall always be with the Lord. " (1Thessalonians 4:14-17)
It's necessary to figure out what Paul means based on other things he wrote or other passages of Scripture rather than ideas we may have presupposed on our own from what we've been traditionally taught. The Bible should be used to interpret the Bible (which is an especially important point when interpreting prophecy, but that's another subject).
In the end, he choose not to want to die because:
"Nevertheless to remain in the flesh is more needful for you. And being confident of this, I know that I shall remain and continue with you all for your progress and joy of faith . . ." (Philippians 1:24-25)
Thank you for submitting your question about apostle Paul in heaven.