Board Waist Width

Hi,
Here is the situation...
I recently found a good deal for a new snowboard but mistakenly ordered it before checking the waist width (or even considering it!). My boot size is US10.5 (European 44)and the waist width of the board is only 245mm! But perphaps it is not as bad as it seems? - i could get a boot size of US10 (meaning less room for socks)and considering im a freeride snowboarder i prefer a stance angle of F +21/26 and B +6/9. But I was wondering what others thought and your experiences with similar perdicaments. I read somewhere that you can sand down the tips and heal of your boot but im not sure if I want to go to those extremes. Sorry for my bad english im swedish

Thx
Bjorn