That is not true in my 3. We left Beaver Creek at 75% charge and regen was never limited coming down either Vail pass, down from the tunnel or down Georgetown hill.Another reason NOT to charge in ski country:
Since Tesla crippled regen with an update a few months ago, if you have more than about 60% charge when you exit the tunnel coming back home, your regen will be limited and you will need to use your friction brakes a good bit; and even more so if you parked out in the cold all day.