You can save a lot of time on the initial install if you postpone the added content such as Independence, VIs and synths. You can always do that part next week after the sale's over.
I elected to skip most of the VIs, but couldn't resist the IR collection. It was only 280 MB. Well, after half an hour it's only at 53%, so that may have been a mistake. I'd suggest deferring everything except the core product until the smoke clears from Magix's server room. You can always learn about the accordion in January.