I did Cincy to YellowSprings on the LIttle Miami path last weekend, and temps were in the 40's in the morning and up to high 60's by afternoon. It's warmer now, but by the end of this week it looks like it'll back to about that. Once I got out of the city and onto the trail, it was busy and there was a pretty steady headwind on the way north, but flat and easy to navigate. Basically you don't have to think at all about where to turn because there aren't any until the little miami trail and the ohio to erie trail split in Xenia. In the northern half, there are a lot of farm fields where you could probably get away with stealth camping, and the John Bryan state park and Caesar Creek state park both have campgrounds.