We had a residential (apartment size) that we put in our TT and it was wonderful. We got an inverter to run it off DC while traveling, but before we got the inverter, we traveled several times without it running and the food stayed cold or frozen. We have now moved up to a 5'er, but I sure miss the extra room in the fridge.
2017 Ford F350 Crew Cab 6.7L 4x4 DRW