I would think anything over 400 for insulation is complete overkill. I run uninsulated with good socks into late november/early december. If you're willing to pay, Crispi has their Nevada Legend GTX with 200 grams of insulation. Well worth the money you would pay!
I can't, in good conscience, recommend ANY Danner product. I would hunt in my slippers before I buy any pair of Danners. They have become a cheap, made in China, low quality, overpriced product with a good warranty. There's several of these in the hunting industry, so that description may apply to other products and brands as well. I've never seen a pair of Danner's run by myself or anybody I know that lasted longer than +/- 25-50 miles. And by the end of those miles, they're basically in tatters and completely broke down and unusable. Danner used to make great boots, but as of late, you're better off with Walmart or Big 5 store brand.