Are you turning the ignition switch/key as far as you can to the fully off position? It will not completely turn off as the transmission is in neutral however it should power down most of the devices and not allow the electronic speedo to accumulate miles.
I have the push button start and when I power down - everything is off when I follow the 4 down tow procedure in the owners manual.
Towr: 2007 Country Coach Allure 470 - 37 Sunset Bay Cummins 400 ISL, Coach #31563
Toad: 2016 F150 King Ranch - 3.5L EcoBoost 4x4 Supercrew (curb weight 4,775 lbs)
Toad: SOLD 2007 Jeep Grand Cherokee (yes, it has a Hemi) (curb weight 4,720 lbs)