With all of the public land in the path, you should not have the crowds at all places. Just the advertised ones around towns. There are many state parks, public forest areas, lakes, rivers, and parking lots in the path in mostly remote urban southeast Missouri. MDC and NFS has lots of ground. Any mountain area around Arcadia would be neat, Taum Sauk, Bufords, Shutins, Silver Mines, etc. Lots of little lakes too for a boat.
The eclipse lasts for hours and has 2 minutes of totality around 2 pm.