Got very encouraging news from the sports doctor today. The MRI showed that the stress fracture is healing nicely (I wish I asked for the pictures, it looked pretty cool). I'm glad I stopped running when I suspected I had it. That time off served me well and now I'm really glad I played things safe.
As a result, I can start weening myself off the pneumatic boot. The minute I feel any discomfort in the ankle, I am to put it back on though. Once I can go a full week in total comfort without the boot, I can start to run again. When this will happen exactly, I have no idea, but it should be sooner than the 6-8 weeks I had originally thought I might have to take off after today.
I'm stoked about this news. The doc said I should definitely be able to do the elliptical machines at the gym for cardio. I'll add that to my workouts starting tomorrow. In the meantime, the weightlifting has been going well. It can't compare to running obviously, but I still am really enjoying it. I'm hoping a little extra muscle all around (but not too much) will help make me less injury prone. Worth a shot.