110.14(C) is a general requirement for all electrical installations under the code. Why would you think it doesn't apply?But where does 215.2(A)(1) say the second sentence applies to 110.14(C) determination? The subject of the first sentence is ampacity. The subject of the second sentence is size. 110.14(C) requirements are regarding ampacity... and says nothing regarding size.
The second sentence of 215.2(A)(1) does address the minimum size of a conductor, BUT that minimum size is determined by allowable AMPACITY. The determination of ampacity must comply with the temperature limitations in 110.14(C).