Let's say a user has 500 initial reputation and they post a question that goes to HNQ. The question gains 100 upvotes in 2 days and then the upvoting stops. So the user now has 900 reputation due to the rep cap.
I was wondering for example what would happen if two months later theoretically 90 users unupvote the question? Will the user go to 1 reputation even though he had 500 initial reputation, or will it stop at 500?
To put it better, in case of unupvotes, do you lose the reputation that you didn't get due to the rep cap?
I know the question is not really that practical, and I'm not going into why that many users would do it, but the situation if it happened, what would happen to the rep.