When my P85 was new I saw 272 once on a range charge (firmware 4.x), a year and a few months later, and 49,000 miles, I see 251-256 on a range charge.
In the end, miles of range on the display don't matter because driving conditions are never the same. Some days I see 255 on my range charge but end up burning more wh/mi because of less traffic to be in line with (and therefor get a slight draft from), or there is a headwind, or whatever.
I'd only gripe if I don't get at least 72kwhr from my pack from 100% to charge now on the display. And, well I'm not going to push it that far every time to make sure I'm getting my capacity.
This is one reason I wish we had the option to display SoC on the center display instead of miles. I use the estimated miles display from the average on the energy usage graphs to really see my range.