LOT released detailed maps of the derecho, based on survey info and some measured wind gusts.
Looks like there was a 5-8 mile wide swath of winds >80 mph in northwest IN, with a much larger area of 70 mph (and some narrow 80+ swaths/spots mixed in that zone too). You can see some pockets of 100+ mph in extreme eastern IL, one just east of the IL/IN border and another over toward Gary and Portage. They don't have it labeled in the legend, but I assume the dark purple circles are 110 mph, because those coincide with the areas that LOT mentioned in their writeup.