ItsIt's limited to the range of the spell
The glyph of warding spell description says:
When the glyph is triggered, the stored spell is cast.
That's it,: the spell is cast with all its normal statistics including range.
While the trigger of the glyph can be unlimited in range ("Trigger when I move 12,000 miles away") the spell that is cast is cast from the gylph with all its normal limitations.