It will never reach level we see in Iceland ever again, we have to accept that.
I said it in previous comments few months ago
https://www.vlr.gg/post/128689/viewership-cs-and-val
Iceland was the perfect storm, teams that have NEVER met before meeting for first time ever, in a LAN environment, with hype behind all the regions due to the unknown. The 'unknown' is now gone, the hype has lessen, we will never see the Iceland viewer number again (and that's OK)
bonus comment: someone thinking 1.5m viewer in Berlin 2 months ago: https://www.vlr.gg/post/128867/master-berlim
edit: forgot to mention Shroud streaming, when he was at the height of his co-streaming popularity as well