I fear that South Dakota may well be the outlier, and many more congested areas will see numbers and rates closer to what NYC and NJ are experiencing. Here in Maryland we have several counties with over 400 positive cases, we are gaining over 300 positive cases per day as a state, and our test results are still taking 7-9 days to process. we are also way behind other areas on administering tests, for some reason we have struggled to get a decent number of test kits.
I would REALLY, REALLY like for your thoughts above to be accurate, but my fear is that the East Coast congested areas will more closely mimic NY and NJ than we will SD....
In addition, the shelter in place and social distancing isn't to stop the virus - it's to slow it down enough that the ICUs, hospitals, and healthcare professional are not overrun and wiped out. Here in MD we are starting to experience a strain on the healthcare system, and we're just getting started. I can't imagine what NY and NJ are like.