If it were me, I'd keep. I think they look *really* good on you, and even though it's the middle of winter - I think these look fabulous. And yes, I would wear white jeans in winter, if I had a pair that looked as good as these. I'd actually be more inclined to wear white jeans in winter than coloured jeans. I'm thinking that this is because I see white as just as much a winter colour as a summer colour?
What do you think? White in summer evokes whitecaps on ocean waves, and yet - it also means snow in the winter.
In the meantime, it just occurred to me that if you were wearing white in the winter, you might want to pair the white with colours that you'd find in nature during the winter? You wouldn't necessarily find brights with white in the winter, but you would see grey (leaf-less winter tree limbs), and you might also see deep and dark greens. You'd see dark stormy ocean colours, but not so much turquoise. Does this seem silly? The idea that white in winter will look beautiful with whatever else is going on environmentally during that season?
Hope you keep the jeans - they look great on you. As much as they might be supposedly 'out of season', I don't really think they are. To me, white is just as 'winter' as it is 'summer'.