I usually travel with my husband, and usually on airlines with a 1-2-1 configuration, such that I am either sitting next to a window or next to my husband (and even then, we are both in an aisle, in any event). Generally, however, please feel free to wake me if you need to use the facilities. I will usually take the opportunity to use them immediately after the person next to me returns to their seat (except during turbulence).