A couple of points I'll touch on.
Cold winter weather, meaning under freezing temperatures, can absolutely reduce range by 40%. Given, part of that is likely due to the fact that in such cold weather, people use the heater more. AC drains some energy and reduces range, however, Heaters really suck up the range. Even in weather that's cold, but not freezing cold, I see very significant drops in range with the heater on. If you live in Canada or up that way, I absolutely would treat a car rated for 400 miles as one rated closer to 225 to 240 miles in winter.
Also, range isn't just about being able to drive further. As Nick said, his bladder can't go 500 miles anyway. I'm in the same boat as are probably a lot of people. However, anyone who owns and EV knows that these cars charge from 0-50% like gang busters. My Model S sees charge rates from the Level 3 Superchargers that exceeds 1,000 miles per hour in the early portion of charging. Drops way down into the 200's when it reaches over 60% and even slower once over 70% and goes at a snail's pace over 80%. As such, just because a 300 mile range car may be more than enough for most people, charging a 300 mile battery after a 280 mile drive will take longer than it will to put 280 miles of range back into a battery that's capable of 500 miles in range. Therefore, charging times will be much, much less than those with smaller capacities. I still make most of the same supercharger stops in my 2019 Model S that has a 360+ range as I did with my prior Model S that had a 235 mile range (after degradation, started off at 265), yet, in the prior car, I always spent over an hour charging. In the new one, closer to 35 minutes. Thus, for the same exact trip, I spend roughly half the time at the charger with my higher capacity battery, despite making all the same stops.
In addition, for current non-EV owners that still fear range anxiety, the longer the range car has, the more that will ease. All EV owners learn how to maximize the return on their battery. But, for those that have never owned it, all they know is it takes longer to charge than put gas in and worry that they'll run out of battery. Having much higher range figures, whether anyone actually uses it or not, will go a long way in convincing skeptics at finally making the transition to EV cars.