We did it in 2 weeks
What did we do? Find services to run the Green Party conference online, quickly eliminate unsuitable ones, get a demonstration from two of them, picked one to go with and then set up a completely online conference in one week.
Unlike the consultants quoted in the article, it was not a case of creating new software or installing existing software on our machines. We just chose which software as a service offer to use. Nor did we try to integrate it with our existing software. We didn't try to set up single sign on. Instead we sent emails to members with a link to where they could register on hopin.to.
There were inevitable user experience problems as there had been no time to train anyone except the speakers and the digital support volunteers. But still 350 people took part on Saturday. We can an online video conferenced help desk all day, sorting out user problems as they occurred.
The big company mindset and rules prevents rapid adaptation to changes in the environment. Expect both the biggest and smallest to collapse over the next year.