Did I see a meteor or a re-entry?
Partial answer only.

120 degrees of sky in 5 seconds or so.

120 degrees in 5 seconds is about 0.42 radians per second. At a distance of 70 km (roughly the distance where an overhead meteor would start to glow visibly) that would be roughly 29 km/sec.
That's a nice number for a meteor.
But it's quite a challenging number for an originally earth-launched object to achieve during reentry unless it's done some planetary flyby's to change it's orbital energy relative to the Sun.
I know it's been almost 6 years now, but if there's a chance that the apparent rate was a lot less than 0.4 radians per second, it would open up the possibility of a reentering artificial object.
If not, I think it is more likely to be a meteor, though reentry of a deep-space bit of space junk is not impossible.