That would have to be tested in court -- and it has not been. I live alone, so your guideline would be that I can have ONE firearm that's unsecured. My preference might be to have multiple, loaded firearms rather than to have to reload in the event of a confrontation. Or I might prefer to keep a firearm in each of several rooms rather than carry a gun from room to room. That's my plan for self-defense.
If self-defense is a "core right" (which the SCOTUS has now deemed it, in both Heller and McDonald, then any law infringing on HOW an individual elects to provide for his/her self-defense in the privacy of his/her home is going to have some high hurdles to overcome.