If you're looking for a meeting place or a good stop around ½ or halfway between Detroit and Endicott, you can try Erie, PA, which is almost 4 hours east of Detroit, or about 4 hours west of Endicott.
Other possible places to stop near the midpoint include Conneaut, Weeds Corners, and Clymer Center.
About ¼ or a fourth of the way, you can stop at Lorain, OH. This is about 2 hours southeast of Detroit.
About ⅓ or a third of the way, you can stop at Cleveland, OH. This is about 2½ hours southeast of Detroit.
About ⅔ or two thirds of the way, you can stop at Olean, NY. This is a little over 5 hours east of Detroit, or about 2½ hours west of Endicott.
About ¾ or three fourths of the way, you can stop at West Notch, NY. This is about 6 hours east of Detroit, or about 2 hours west of Endicott.
If you drive straight through without stopping at all, the total distance is 521 miles. The distances shown above don't include local roads to get into each town, so if you're planning a long road trip, make sure you factor in traffic and road conditions, rest stop breaks, and interesting detours along the way. If you're in a rush, you can do the trip with zero stops, and your total travel time would be around 7 hours, 53 minutes.