Do you think he could easily walk another 1-1/2 miles? Depending upon when the walk is to take place, you might want to increase his distance each time you walk. I would think unless you are certain you would use it, the stroller will be just be in the way.
We walk usually a little over a mile each day, and Ruby takes her sweet time, while Reno wants to fly, so most days I end up carrying her part of the way