"Your download will take ~4 hours to complete"

IMO, you should upload the file to a GCS/AWS/Azure/Oracle/etc storage bucket, set the permissions to "anyone can access" but set the object so that the "requestor pays" for downloads. This will result in you paying under a dollar per month in storage costs, but anyone who accesses your file will pay a few dollars to get your data in seconds.

Maintainng a multigigabyte file that is accessible to the public for free, that can be accessed unlimited times is really not feasible.