will the streamers be able to handle such high viewcount from home?
I'm about 99% sure that's on the streaming service, not the individual streamers. I'd also assume they're using the same service for both their at-home casting and their at-TI2 casting.
Well, the Dota 2 website says August 31 - September 2. so this news is kind of expected. It just means we have 2 extra days for the group staged to watch