While armed robbers are unfamiliar with the house, they are also generally rushed. What is of concern these days are home invaders who are thorough, determined, violent and willing to spend a day destroying your home for their purposes.
What was unsaid was that your even having a basement is unknown to them, much less a safe room where you could comfortably stay for some days. A passive, fiber optic surveillance system to tell when your home was no longer occupied would also be valuable.
Multiple shotguns that are stashed throughout the house would be my choice of dealing with home invaders who are thorough, determined, violent and willing to spend a day destroying your home for their purposes. Various types of ammo from slugs to 00 buck will handle everything.