Realisticly you'll need a 1" pipe and #10 THHN/THWN-2/MTW...
The Code does not provide field electricians with an 'out' such that they can rejigger standards based upon their opinion or calculations.
That from time to time something is over engineered is balanced against the reality of the hazard of under engineering.
BTW, W a y back in the day -- everyone thought that if it worked it was safe. Then electrical fires were invented...
And the NEC was born.
