Colder the air, the denser it is and hence greater oxygen content. So that’s all to the good. BUT, air box design is a bit more of a science than merely having as big a hole as possible. Boxes are designed by a combination of shape, volume and intake hole to achieve an optimum air flow at a resonant frequency designed to be at a point where torque might otherwise drop off due to engine characteristics. (Helmholtz Resonance principle) So, don’t throw away the bits you’ve drilled out, you may wish to stick them back on!
