Here's my answer: when deaths are roughly equivalent to the flu. Influenza seems to be a pretty good threshhold - we have shut things down locally when it gets out of hand, and influenza and pneumonia) is a
top 10 cause of death.
The CDC states that there are between 24 and 62k deaths for influenza between October 1 and April 4 - 183 days. let's take the upper bound of 62k and divide by days, and we get 338 deaths per day on average.
So - I'd say we are past this when our daily national death rate is consistently below 340 per day, or 0.1 per 100k population. That's a rate of roughly 10 deaths per day for the state of Michigan. Michigan has had less than 10 deaths per day (7 day moving average) since July 18, so I'd say they are well on their way. At long as Michigan can keep Rt at or below 1.0, I'd say you guys are in good shape. For Florida - they would need to be roughly 30 per day - no where close.
Honestly, I'd take another look at Whitmer vs DeSantis.