Data transfer speeds depend in your internet connection speed (“up” speed) and the server’s data loading speed (the latter can vary depending on how busy the server is).
If you are not using FTP upload yet, it can help. The data may not transfer quicker, but it will be easier to keep track of what is completely loaded versus not. Leave the connection open, check for any incomplete, and “resume” dropped connections. For this much data, that may happen a few times. You’ll need to accept the security certificates each time, so watch for that.
Current instructions for UseGalaxy.org: