It might be worth starting to look at before it suddenly becomes urgent...

As the ship sinks, they've possibly already lost nearly a third of their previous "top 1%".

["The company noted that over 70 percent of users flagged for excessive bandwidth choose to either upgrade to a custom plan or lower their bandwidth usage." - Without further breakdown, that's 30% that didn't choose either option, who presumably jumped or were pushed.]

I suspect a lot of them won't be leaving for real when they start shopping around for alternatives. The numbers I see looks in line with what you would normally pay for cloud services.