Unfortunately, you are assuming that because it is illegal to use the regular military inside the US, that would not be done in an “emergency.” That’s hard to know, especially since it is no longer a citizen, but a mercenary, military.
You may be right about the unwillingness of the National Guard, but if it had already been federalized prior to the emergency, state governors would no longer control it. The various state Guards could be used in other states where they might be more compliant.
All of this is hypothetical, but I stand by my original contention that no ragtag band of civilians with assault rifles can last long against, much less defeat, a professionally trained military with modern technology.
Best case, we never have to find out..