You do have a big foot. I am not sure what to tell you. I will say that you are on your feet skinning for hours versus minutes for riding. So you will be on your feet hiking for the most part.
For myself, I value comfort of my boots more than I value a tight assed fit. So I run pretty true to size. Fortunately, for most boots my size (11) works great for me. On occasion I have gone down a half size due to something like heel lift.
Just keep in mind you spend the majority of your time skinning, not riding. Nature of the beast. The time you do ride will be the best turns you've ever had. Time after time after time...