Same problem here. Apparently it's a widespread issue on the Velar, and since there's no official fix via replacement parts from JLR that's available yet (they're still working on it), some dealers have been left to attempt a fix it on their own. But now JLR have been discouraging dealers from performing their own fixes and instead are being advised to provide the affected Velar owners a loaner until it is resolved, because in cold weather, it is most certainly a safety issue, especially during night driving. In my case, it only needs to be under 40ºF for the all side windows to fog up completely, while even the edges of the front windshield that's not covered by heater elements also get foggy. I can only imagine this being an even bigger issue for those without the heated windshield option. I literally cannot see through my side windows at night without rolling them down.
According to my dealer, the TSB issued in early November is not the definitive fix as most Velars that have been "repaired" with this TSB ended up returning to the dealer with the same recurring fogging issue, but even to worse extent.
My Velar has been at the dealer since last tuesday. They are working on the fogging issue, replacing a faulty pano roof seal (unrelated to fogging), and to hopefully sort out all the electronics and infotainment gremlins via a software update (though I'm not holding my breath that it will be real fix to all issues). I was given a discovery sport loaner that's far from an enjoyable drive. Not a fan, but at least the windows don't fog. As problematic as my car has been since the beginning, I do quite enjoy driving it and can't wait to get it back soon.