GPSOverWifi is a Novatel MiFi device driver. I seem to recall need it to USB tether the device to my MacBook Pro (Late 2013) Retina. I installed mine in 2013, and it's never given me any issues, even after I stop using the device over a year ago. Until two days ago when I installed Sierra (Build 16A323).
What appears to be happening is that the driver is stuck in a loop causing it to open persistent tty sessions until all available sessions are used (as defined in sysctl). It won't make any difference what you set the soft or hard tty caps to because GPSOverWifi will gratuitously eat them all (and refuses to share.)
The issue affects anything that requires a tty shell, such as SSH. So you won't be able to remote into the system. In fact there will be no available ports to connect to.
You can test by renaming and killing the process, as you mentioned above, and openning up a shell. You should now get to a prompt.
If you execute the file from a shell, you'll get the following:
Sep 16 18:39:12 GPSOverWiFi[9288] <Critical>: openpty() error: Device not configured
Sep 16 18:39:12 GPSOverWiFi[9288] <Critical>: openpty() error: Device not configured
Sep 16 18:39:12 GPSOverWiFi[9288] <Critical>: openpty() error: Device not configured
Sep 16 18:39:12 GPSOverWiFi[9288] <Critical>: openpty() error: Device not configured
Sep 16 18:39:12 GPSOverWiFi[9288] <Critical>: openpty() error: Device not configured
Sep 16 18:39:12 GPSOverWiFi[9288] <Critical>: openpty() error: Device not configured
Sep 16 18:39:12 GPSOverWiFi[9288] <Critical>: openpty() error: Device not configured
. . . rinse and repeat . . .
I'm not sure why the app suddenly decided to go rogue (and I probably won't know until after I've reversed it). But it appears that something may have changed in the way that MacOS is handling or configuring tty sessions, or something in the file's decision matrix is not being satisfied thereby throwing it into a loop. Lots of speculation at this point.
Cheers!