Lets assume that the display uses quite high amount of power from a computer point of view of constant 30 Watts (Apple M1 Pro peak power consumption on max load).
On an one hours drive it will then consume 30Wh or 0,03kWh
with other assumption of 20kWh/100km(3.1 miles/kWh) consumption while driving means that you lose roughly 150 meters (about 500 feet) of driving distance per hour because of that 30W drain.
In real world I would be amazed if that display/navigator consumes that much power so in conclusion it has little to none effect on your range.
On my Prius I used to always turn of the navi display while driving at night, because that light shining to my eyes while driving was distracting, so I would like it to have an display off option, but not because of power consumption.