Test the speed of the Internet access before sending your file.
For instance, these are the estimations for a 100G file :
Internet < 30Mb/s upload : very long transfer (around 12h30)
Internet > 30 - 60 Mb/s upload : long transfer (around 6h)
Internet > 60 - 90 Mb/s upolad : standard transfer (around 3h30)
Internet > 90Mb/s upload : fast transfer (around 3h)