Too big for your own boots!

My daughter's partner was fascinated with my knitting over the holidays and said that he'd never even seen hand knitted socks before so I've made him some using the left over yarn from hubby's Christmas jumper. He's got big feet but I may have overdone the size however they're to wear on top of his own socks and inside his steel cap work boots. He works outdoors most days so I hope that they're warm enough for him during the winter months.