My family and I are moving this weekend. It came time to move all of the hanging clothes. I started carrying the clothes about 8 in each hand. After the first trip I said "There has to be a better way." I looked through my scraps and found a sturdy piece of 1" by 1" by about 18" piece of poplar left over from another project. I found a hunk of line about 6 ft long and did a bunch of half hitches on the top of my hand truck and presto I now have a way of carrying about 30 items at one time. It will remain free standing while loaded, which is really convenient to hold it all up while unloading. I can easily bump it up and down the stairs since it isn't really heavy.
I used poplar because it was available. The main thing to look out for is strength. 30-40 items of hung clothing can be heavy.
My hand truck has a nice perpendicular handle coming off the main upright. Make your half hitches tight and then pull the left over rope between the handle and stick. It will help to tighten it even more.