I tried on a pair just like that... well, I tried to-they would not go on.
my calfs are 16 now, probably a little bigger back then. I find that if they don't unzip especially, they really aren't going to go on. but each show is different - they could fit !
I noticed tj maxx has a lot of boots right now. granted, they aren't that cheap - I bought a pair recently that we're $60.. but I had to have them. they don't ip or anything, but the calf portion is wool or something.
maybe you could look for something like that? otherwise I would suggest looking at some wide calf boots.