I've found that all Lake shoes run at least a .5 size small. I'm a solid US 10.5. My summer shoes are 44.5 and the boots are a 46. Both fit comfortably. I don't believe the MXZ301 sizes account for heavier socks at all, and recommend at least a full size to 1.5 bigger than you normally wear.

On the bright side, your size is at the end of the bell curve, so there tend to be a few unsold. Check www.lickbike.com. They had the best deals at the time I bought.