I have Komplete 14 standard. Is the update really 300 gigs or would it be less than that?
The overall installation is 300 GB, however you don't have to install everything your can pick and choose what you want to install.
I purchased Komplete 13 Ultimate when it came out. It had so much stuff packed inside, I just installed only what I needed. As time went on, and My music creation advanced, I opened Native Access and installed more Instruments like (horns, and Symphony's), Effects and applications.
I suggest that you pick and choose what to install and before you install anything, install to an external separate drive if using a laptop. If using a desktop, then install an additional internal drive and save the Komplete library that you want to that drive.
Install Native Access > Open Preferences > File Management > Look for Content Location and point to a folder on your additional External or Internal drive for your Komplete Library to be stored. View instructions on Youtube https://www.youtube.com/watch?v=vGD4rAHu1gQ
I hope this helps