If you want a graph that is far more accurate than % or miles display, bring up the trip consumption graph. Bottom nav bar, in the 'extras' up arrow section.
If you set a destination, it will show you what it thinks it will use over the entire trip, in a predicted battery graph. It updates based on SOC, so it takes into account variables like how fast you are going, uphill/downhill, a headwind, and temperature. When I was doing some longer distance travel the estimates were spot on +/- 1% from the original prediction when I arrived. I'm fairly certain that it uses data from other people who have driven that same path.
Random example from web: