You might not be cold when you are actually skiing but in the morning and evening when the sun isn't up it certainly is. You will need more than flip flops, beach shorts and a t shirt anyway ?That's skiing, never understood why people think they are going to be cold skiing and your rarely wet.
I tend to thing of wet feet when people are walking around in snow. I hate having wet socks. Probably inaccurate, do people still wear moon boots?, but the thought is there.