To TPK or not to TPK
Im running The Fall of Cyrog and my players defeated Cyrog. Upon Orcus stepping through the portal and Mind Flayers appearing, the party decided at level 8 that hey why not fight him. After strongly suggesting the mind flayers are a diversion so they can get away, my experienced players pressed on. One person decided to use the Drax strategy and fight from the inside of orcus, the rogue ran away, the warlock straight up died, and the rest of them are all pretty close to unconscious.
I would like to keep the campaign going for my own selfish sake, but I feel like my players also should get humbled. Next session begins with the continuation of this fight, where I fully intend to summon a nightwalker. They will all get a turn to run before this happens. Ive never TPK'd a table before and don't know how to feel about it.
For those who have more experience then I, what would you do?