If I had the same situation, I would look at a gravel style bike to go with the trailer. I commonly use my Burley Travoy for Grocery store runs and use a combination of many different bikes to do it, including a road bike, gravel bike or even a single speed. A gravel bike is the best mix since it should have a large range of gears and a more aggressive riding posture, plus room for bigger tires. It seems that the 650B (27.5 MTB) is popular these days, so you can change out tires as needed for terrain and that's what I would do.