I don't have a Nissan but I did once have a 1500 Dodge. I had an 8' pop-up camper on it. The camper had no basement, no slide, no bathroom, no sewer tanks. I removed the spare tire from the truck. With just me in the cab I was 700 pounds over the truck's GVWR. I added air bags and load range E tires and ran it for a year. It did okay but I was always counting pounds of any gear or people I put in it.
A few years later, when having my differentials serviced the technician showed me that a couple things were broken inside and recommended I not tow with it anymore. I don't know if hauling overweight with the TC was responsible or not.