I have been towing kayaks for years now by strapping the nose of the kayak onto a bit of wood extending from the pannier rack. It has worked ok, but the kayak still jiggles annoyingly particularly with heavier kayaks. Now I have developed a sufficiently rigid towbar that attaches easily to the bike using my standard ball joint hitch, that allows kayaks of any length to be towed with ease, even my 5.8m 40kg double sea kayak is relatively pleasant to tow along. Another great feature is the long extension can be removed and a bin attached to turn it into a shopping trailer. For more info on people towing kayaks see Fossil Fuel Free Multisport 2012 and 2013 and instructions. I still haven’t found any enthusiasts to cycle over the Port Hills with a kayak and paddle to Quail Island, then return. One day…
Nothing new about that trailer and hitch arrangement, decades old. As for distance, how about towing your kayak to Havelock and spending a few weeks paddling in the Pelorus Sounds? Talk to George, he did it decades ago and I paddled with him for a week before someone else took over my kayak for the next week.
He might also have towed to Lyttelton and paddled to Quail Island, again a decade or more ago.