[inamberclad]

I'm having a hard time finding good atmospheric density charts that go all the way to orbital altitudes, but this one looks good: http://hildaandtrojanasteroids.net/Atmosphere_model.png

Basically, there's already nothing left at their new planned altitude. In either scenario they'd need to burn fuel in order to compensate for irregularities in Earth's gravitational field, but I assume they've run the numbers internally.