It is indeed, maybe iodine enables one to do better on a mostly ketogenic diet, but the Eskimos were an extreme society that it would be difficult to emulate elsewhere, so even with iodine, it's probably a risky approach.
I've noticed that raw vegans and fruitarians tend to report many of the same symptoms as VLCers / VLC Paleo dieters, such as worsening cold tolerance, and one common tendency is low intake of resistant starch. Wish I had known about RS long ago. I think I would have seen the connection quickly and more quickly realized that there was something seriously wrong with VLC and all diets with low intakes of RS.
I had found that increasing my fat intake temporarily helped to make me feel warmer, but then it declined again. Unfortunately, by increasing my fat intake, I lowered my carb intake even more. It was RS I was missing, not eating fat. It seems that getting fat from one's own bacteria helps warm the body more throughout the day than just eating lots of fat at meals.