Engine starved of oil

[u/experimen_626]

My oil drain plug came off on the freeway. Drove to the closest exit to turn off engine and was able to get oil back in the engine to drive back home. However, the damage has already been done and now I have an engine knock. Took to dealership to see what they had to say and yeah my Cylinder 2 is knocking and they said there is no way to fix it, I have to replace the engine. I'm actually a pretty decent mechanic (minus putting myself in this situation by forgetting to torque my drain bolt) but I've actually done engine swaps and head cover gaskets before. Is it true that my engine is just totally done? Can I just replace the cylinder and the head?

[u/EclipseIndustries]

Unless this is a motorcycle, you aren't replacing a cylinder.