Try to kill them one by one silently

You use a sleep spell to kill two sentries who are alone in a corner of the camp. You just cut their throats when they are sleeping because fo your magic.
However, after you kill two more goblins, you make a mistake and you reveal your position, the goblins start to attack you with all their weapons, you burn some of them with a basic fire spell, but you are pinned behind a big piece of wood. and your magic shield will not last longer than 6 more seconds.
They keep screaming "Surrender human!" and the girls in the cages are crying and screaming in panic.

At this moment, you have to decide what to do.

Surrender and hope that they have mercy, maybe you can escape later.
Cast a fireball spell and try to kill them with a huge explosion and prepare to die if you fail.