You can do Range Mode and Insane at same time. The only thing that insane mode seems to affect is acceleration, the rest...like normal driving, seems the same. In reality, Insane mode is great to show the drop dead acceleration for your first time Tesla passengers, but Sport mode gives you more than enough punch for everyday driving. I usually leave Sport / Range on, and go from there. But I have done Insane and Range a number of time, works fine, same range as far as I can tell. Not sure why I don't leave it in Insane all the time...though I am a proponent of doing a further Eco mode too, as I like to hypermile for fun.