For your part of the country, I wouldn't think you'd need to go overboard on insulation. However, I've never liked cold feet.
In Minnesota I wear good constructed leather, Gore-tex, Thinsulate boots (800-1000 grams) for colder weather with a pair of Mohair sock (not wool).
The former wear much longer, don't sweat and are the softest sox I've ever worn. I get mine from:

austins mohair: angora and boer
jim or ada austin
r.r. 2 box 41 b
harmony, mn. 55939
507 8866731
[email protected]
mohair items created by 15 stay at home moms for sale
http://www.bluffcountry.com/austins.htm

They're not cheap, but they last a long time even with wearing them regularly and they are warm. I've got a pair on now to keep my feet warm.

I'd say in your area for insulated boots look more at 200-300 grams of Thinsulate. Ask your friends too what keeps their feet warm.