Realistically I think it depends on where you work. I can’t imagine if your workplace has a smart causal dress code you can get away with nothing new for a whole year. Someone would notice you are wearing the same clothes again. So swapping or thrift-shopping would be a must. The problem with swapping or thrift-shopping is that it is pure chance to have something that fits. And alteration costs.
I haven’t bought new clothes for a while, only because I mainly work from home. And I’m super lazy.