Will DSM notice it being any darker? I might see a hint of it right now but nothing earth shattering. It's pretty amazing to see the sun look like a crescent.
No, those in totality will stay in almost full light until just minutes before totality. The sun is really so bright that to start to see noticeable darkness it has to be almost totally covered. It doesnt even get totally dark like at night in totality. It is a really strange darkness, its dark but also light at the same time, similar to twilight, but also different.
If there is any dimming here it will be very minimal.
Daughter and I went to it in 2017. Would have liked to this year too. It really is amazing to see. But she is in college now, and the traffic looked insane.
If you ever get a chance to go to a total eclipse its worth seeing it.
Edit: It does appear we have a slight bit of dimming, in the DM area but not a lot, but not really darkness at all.