Do you find that you often have pumped milk that is wasted?

A lot of times my baby will only drink 2oz. at a time and I find that my milk goes wasted if I try to feed her from a bottle. I've resorted to only making up bottles that hold 2oz. because of this but even then, I find that she doesn't always drink it. Also, sometimes when we're going out, I will take pumped milk out of the freezer, let it thaw, and then she doesn't even end up using it.