First, the Duck River Watershed mileage chart is wrong. It's actually over six miles from Leatherwood Bridge to Littlelot Bridge - so that will slightly extend our too-short trip.
Second, our take-out in 2011 at the McEwen's farm was farther upstream from Leatherwood Bridge than we thought. Here's the aerial view that shows the farm, and you can see the triangular shaped field down by the river where we loaded out:
If we put in there in November, we'll get to paddle a full 1.5 miles before going under the bridge that we had been using as our starting point for calculating mileage - so add that to our trip distance as well.
Running all that through the RRCC abacus, the new total from McEwen's farm to Littlelot is 7.5 miles - a reasonable distance.
Now here's the best satellite picture of all:
A veritable Horn-O'-Plenty of gravel bars, just one mile upstream from where we would take out at Littlelot Bridge. So, while not an adult sized serving by any means, we can count on paddling at least 6.5 miles on Saturday which should be enough for the leisurely approach we want to take on this trip. Plus we can put in and take out easily (and legally) both places.