Hi Samartl,
UEFN is tightly integrated with the ‘live’ version of Fortnite, so the students will get an error when they attempt to ‘Launch Session’ if there is a version mismatch.
You could disable ‘Auto-Update’ for Fortnite in the Epic games launcher, at least that way the bandwidth would not all be slammed at once.
Also, the scheduled releases are listed on the roadmap, so that could help you anticipate the updates.
Good luck.