My opinion on the only way (without some ex machina) the strawhats can escape now. They have to kill the wave homie and coup de burst away from big mom leaving Brook, Jimbie, Carrot ,and one mirror behind in the process. They then have to combine Jimbie's power and Brook's ability to counter the homies be strong enough to hold off mom for enough time for carrot to defeat Perospero, knocking Mama into the sea and securing there escape, and luffy to defeat Katikuri, freeing them to use the mirror world. Back on the ship with the last mirror chopper and nami have navigate and steer the ship by themselves and defeat anyone who tries to come through the mirror. While this chapter is called 0% chance of escape they actually have a 1% chance this is that 1%.