Please cash in at least some of that; it's too sad to think of a conventional amateur investor approach of "always hold out for more" wiping out that potential fortune. Take your 5000x gain and be happy with that phenomenal performance instead of being concerned about the infinite "I could've gotten more if I just sold on Magic Date X".
A materialized gain that you can actually use is more valuable than a paper gain that may not be there when you need it, especially in an instrument as volatile and immature as Bitcoin.