Try Naturalizer Wonderful Plus. They are for large calves & fit me really well. They aren't cheap (I paid $145 at Nordstroms 3 years ago), but they are still in great condition & I wear them a lot during the winter. If you still need a bigger size, a good shoe repair shop can cut the zipper out, add some extra leather on each side & put the zipper back in. A friend of mine had that done to hers for less than $25 & you can't tell at all. Good luck!
