I would recommend considering carrying one in the back using a rear hitch carrier and one on the front using a front hitch carrier.
With a scooter on each end, you won't get the weight distribution issues that result from carrying weight on only the rear hitch. You can keep each scooter covered with a wind-proof cover so it's protected from the sun, the weather, and road grime when traveling and camped. You can use case-hardened chain to secure each scooter to it's carrier and to secure each carrier to it's hitch. There are probably hitch carriers with a tilt-down lower rail for convenience in loading and unloading.
And last but not least, you won't have to deal with the negatives that come with towing ... even something relatively light.