As far as I know, both can be used in the ~는 것 construction. However, despite having searched about these topics, I still have trouble differentiating between them. Can someone explain cases where one would be more acceptable, and why?
정도, 만큼 : describing a size, volume or level
This is so long it could be recorded as a world record.
이것은 세계 기록으로 기록될 정도로 (만큼) 길다.
He is so smart he could go to Harvard.
하버드에 갈 만큼(정도로) 똑똑하다.
@ They have almost the same usage, but 정도 (degree) can be used to explain a fixed point or area in our tacit consent.
Our patience has a limit.
참는 것도 정도가 있다.
But 만큼 needs that additional clause or phrase in the sentence.