8.300-1(b) says demand for a range is 8 kw plus 40% of the rating over 12 kw. 8000 plus 2000 or 10,000 watts which is 41.5 amps
26-744(4) Where a range having a calculated demand of 50amps or less, receptacle 14-50R shall be installed.
26-744(6)bla, bla, bla calculated demand of 50amps or less, shall be cord connected using CSA configuration 14-50P
The domestic range cord supplied with most 12 to 14 KW ranges have a number 8 conductors with a 10 neutral. I don't know what these cords are actually rated for. I imagine the 50 amp cord is #6 with a full sized neutral and costs 5 times as much.
Cords supplied with domestic ranges are rated at 50amps. Residential range receptacles are also rated at 50amps.