I have a little light-weight trailer dolly that I bought at Harbor Freight just to tow the Kar Kaddy dolly around.  I changed the nuts on the handle bolts to wing nuts to make it easy to take apart, and I carried it in the basement storage of the motorhome.
We made a trip from Billings, MT to Ringgold, GA and back a couple years ago.  Not one campground we stayed at all the way down and back, made us put the dolly in a special parking area.  It stayed behind the coach the whole trip.
Since I sold the brakeless Kar Kaddy (really stupid thing to do), I use the little dolly to move my 5X8 ATV trailer around.  It works great!