Short answer, same as last year: it's fine. Wear white whenever you want. Maybe avoid the muddiest days of the year unless your dry cleaner has a frequent flyer program.
Slightly more nuanced answer: Although white knows no season, it can be a little dry. We wrote a little while back about light grey as an alternative, and the whole range of stone, ivory, and other off-whites is generally a bit more sophisticated than the full-brightness original. At the risk of turning our site into WWTFD (What Would Tom Ford Do?), see images from his F/W lookbook above for whitish winter inspiration.