I think that the idea of a world wide "drink the kool aid Jonestown" scenario is unrealistic and irrational.
For one thing, the GB and all their true believer followers do not believe that they will die. They believe they are going to live forever and never die. They are going to survive the apocalypse. Drinking the kool aid is in direct opposition to this fundamental doctrine - "we will live forever! we will never die!"
However, the kool aid behavior has been acted out in isolated family groups, especially among those who have left or been disfellowshipped. There are several cases where the irrational fear of not surviving Armageddon has lead to mass killings within JW families, especially where one individual has seen the kool aid option as the last resort for their family's chance at eternal life.
The promise of eternal life has an evil counterpart - if you die before Armageddon, you get a second chance.
So, the ones who I think are the most in danger from this cult and who would drink the kool aid readily are those who are no longer inside that special golden circle but still believe that jehobah will kill them at Armageddon. They want their second chance. So they will drink and they will spike their loved ones drinks as well.
Many have already. Tragically.