"Frenzi" tan boot at Zappo's (wide calf) for $189.95 *very very cute!*
My friend Dee has a hard time finding boots in her size (11) and she is very muscular which makes it hard to find boots that fit her calves. I found some boots that are for curvy calves and come in larger sizes to help her and others meet their cute quotient even in winter.
Naturalizer "Rewarded" knee high black boot $139.99 (on sale!) and Bandolino "Kisha" boot $59.99 (on sale!)
Zappo's, Bandolino and Naturalizer are all consistent when it comes to larger size shoes and wide calves but you also might want to check different designers at department stores, some also make styles in larger sizes.
"Winter Warrior" quilt boot $298 at Dillard's (All of the boots shown run up to size 11 or larger.)
Need more? Check out J. Crew and Duo for extended shoe and calf sizes.