Electric Water Heater Conversion Kit

I have been considering one for awhile but am leaning to the lightning rod simply for ease of installation (thermostat attaches to pop off valve instead of tank). Only other concern was in the Hott instructions it states not to use an extension cord which is my plan. I would like to run a cord to the pedestal when hookups are available and not have too concern myself when boondocking. This would also keep it from drawing off the MH electric and if for some strange reason I did need to use it off the generator I could just plug it into one of the outside outlets.