A noisy, angry mob of Marxists crowding around your door? First of all, they've imprisoned you in your own home--and that's a forcible crime of false imprisonment right there. Are going to wait until they actually look ready to torch the house?
Say hello to my little friend, SEIU goons.
Because you are not the county DA, you don't get to charge false imprisonment, and without that charge, you're not a "reasonable man". If the DA is a leftist (likely in urban and suburban areas), you are screwed, he won't charge the trespassers.
As far as waiting, you better, again a "reasonable man" would not fear for life until someone lit a torch (remember I mentioned "deadly weapon").
Leftist and jackboot courts regularly use the "reasonable man" administrative law to second guess your actions. If their definition of a "reasonable man" would not shoot, you're screwed.
However, once the door is broken or the torch thrown, no jury would believe a "reasonable man" would not fear for life.
Never believe the cops, prosecutors, or judges care a whit about you or your family, your only friend is the juror, if he is smart enough to get by the prosecutor.