^^^Hope you feel better, Nate.
I spent all day travelling to Southfield, MI for a week of training....flying sucks. Sitting in a hotel room now catching up on emails and the latest Head Case goings on.
A portable amp would definitely fix it by increasing (amping) that 256kbps up to 320kbps. In fact, if you get the right portable amp, you can achieve lossless.
You should try the road up Mt. Evans here in Colorado. It's the highest paved road in North America with the summit at 14,260 feet. Take some O2 with you....