Here's a few other adventures we've had:
Douglas Lake TN. This lake was great for a weeks vacation. Really close to Gatlinburg and Pigeon Forge for the kids on a rainy day, or day away from the water. Giant and DEEP lake with good clear water, although a little cold. We had 2 families in a single cabin with 2 boats. Was a great time for the week!
Cumberland River/Nashville/Old Hickory Lake. Wife and I put the boat on Old Hickory in the morning. Locked through to the Cumberland river, cruised down to Nashville for the day, then cruised back up river and locked back through. Was a great time. It looks like there is plenty to do on Old Hickory if you wanted to make a weekend out of it, and only spend one day on the down/back trip to Nashville. Pretty cool adventure if you can make it happen.
I've heard that Lake Monroe up near Bloomington, IN is beautiful, but haven't been yet. It's on our list for this year to check out. Likewise I've also hear that Laurel Lake in SE KY is amazing. Again, never been, but it's on the list. We also do "date night" on the Ohio River a few times a year. It's a good Friday night activity to break up the monotony of the week. We live in Georgetown, IN, so it's less than 10 miles from the house to the ramp, and there are a few places to get food and drinks on the water. We'll put in, cruise up and look at the bridges then get some food, then cruise around some more. I would suggest finding a similar setup in Cincy if you can. It really is a great way to get some boat time during the week.