I’m normally in agreement with your analyses but I can say from experience that my petrol MINI got 350-380 miles from a ‘charge’ (my electric MINI gets the 100 you state). But the point is that I rarely drove my petrol MINI over 100 miles in one go and so far my electric one has taken me everywhere I have needed it to.
Fair enough :-) I was just going by some stats from Mr Google. It probably depends on the model of Mini and the age of the Mini.