you will have less ability to get on edge with a wider board. So it will impact you. You turn in snowboarding using your edges so anything that lessens the response will make turning harder.
Will it be impossible, no. Will it be much more difficult, yes.
it sounds like you have your heart set on a bataleon, i think you might want to look at the womens boards like another guy suggested, a stiff womens board will ride like soft park board at your weight, you will have to look at thinks like set back etc. but with feet as small as you have options are limited.
I have the opposite problem, I wear 12.5's which is another forgotten size and I use wide boards, my options are limited every year. I know there are companies you can call that will put their other boards graphics on a different deck (usually there is a charge)...see snowolfs NS pandora/summit for more details :P I cant recall if it is the summit or a different one, sorry for any mix up snowolf.