We traveled cross country pulling a 15 foot trailer with home goods in our Galleria - Sprinter 3500 from AK to NY and back. We checked with the Sprinter dealer and the RV dealership to be sure that the van could to it. They kind of laughed and told us it was fine. We did add Sumos to the springs so that helped the handling. So when we had the van checked after arriving back in Alaska, the Sprinter people said that the van was in good shape. Before leaving AK, and again before heading back from NY, we had the brakes and other things gone over. When we got back we had them check brakes again and they were still fine.
The van weathered the trip better than my DH. If I you have ever driven the Ice Fields Parkway, you might understand his anxiety.