Will anyone survive the Great Tribulation?

Yes, some will survive the Great Tribulation. The days will be shortened for the elect's sake, preventing total destruction. Unless brought to its timely end, no flesh would be saved, but because it ends on time, there will be survivors—flesh and blood believers needed for the regeneration of the human race in the kingdom economy.

Les teaches that Jesus said except those days should be shortened, there should no flesh be saved, but for the elect's sake. The elect are believers going into the kingdom. Flesh and blood believers are required to enter the kingdom, so the Lord must stop the tribulation before all are killed, otherwise no one would be left for the regeneration of the human race in the kingdom economy. Because it will end on time, there will be survivors. Les then moves to Revelation chapter 6, where the seals depict the Antichrist (white horse), the Russian invasion (red horse), famine and disease (pale horse), and great death and destruction (black horse), with the sixth seal opening.

Matthew 24:22

And except those days should be shortened, there should no flesh be saved: but for the elect’s sake those days shall be shortened.

Why will the tribulation be shortened or brought to its timely end?

Scripture states the tribulation will be shortened for the elect's sake. If it were not brought to its timely end, no flesh would be saved. The Lord must stop it so flesh-and-blood believers survive to enter the kingdom, ensuring the regeneration of the human race in the kingdom economy.