Break it up into files that can be downloaded by county, state. etc.
No one expects a single file. I don’t.
To put the cherry on top of my 2021 Nobel Prize for file downloading, I just created the idea of having many data file storage servers spread out all across the country in something I’m going to call “The Cloud”. It will allow millions of people to download huge files at the same time. Thinking of offering Microsoft an exclusive, since it’s something they could use when having to rollout big files to hundreds of millions of PC’s during upgrade time.