It is oil temp, so 10 miles or 10-15 mins is not unreasonable, and it depends a bit on outside temps.
It is better to warm up an engine under gentle driving than idling. This is not new nor limited to BMWs.
2012 328iTouring xDrive Black Sapphire
Waiting for: 2016 340i xDrive MPerf. EBII
Previous BMWs - 17 others since 1971.