If you're still at a standstill, you could break the build into a bunch of 32x32x32 structures of parts of the build. you will have to keep track of the relative pos and relative cordinates of each structure block to make sure everything lines up again when reassembling. It can be a fair amount of work though. Not nearly as convenient as if MCEdit was available for 1.13. Sadly, I don't think MCEdit and many other tools will ever be updated to work with 1.13+, Goodbye MCEdit.