Hi. My roommate and I are planning a 70 mile trip. Our goal is to finish at least half but we are going to attempt whole thing. My question is do we both need a 60)L plus backpack or can one of us carry a larger one and one carry a smaller and swap loads to make it easier for us? Most of the stuff we will be sharing obviously so I figured we could pack light. This is our first trip. We do need to pack two sleeping bags though.