2inch tires never failed me in years of biking year round in Northern Wisconsin. Use the saved money from the bike frame, and purchase/fabricate a trailer. When biking, you do not want all of your weight on your back, as it throws you off, and lengthens your breaking distance. Look into the bikepacking threads for frame mounts. If you plan on hauling more than 20 pounds around, you are going to want to heavily modify your gearing to make towing much easier.