Gold ToeMen's Canterbury OTC Extended Sock,3 Pack

Q: Are these wider too or just longer, for large feet?

I'm 6.0', 185 lbs, 12 shoe and these extra large size socks are plenty long enough but are too tight, they don't easily stretch.

Q: Is this a pack of one pair or 3 pairs? thanks

3 pairs. Good value on some perfectly decent dress socks.

Q: Do these socks keep your legs warm?

Not really: these are a year-round item, and one feature I like them for is moisture (sweat) wicking. If you want a warmer over-the-calf sock, Gold Toe makes a merino wool version that I used to use. Those helped me get through Chicago and Boston winters. Good luck!