I'll rephrase: would a ban on carrying guns outside ones own home or property during a declared emergency pass muster?
Very possibly. We still don't know where we are on scrutiny, but even assuming strict scrutiny, a judge could fall back on the old "time/place/manner" test.
A crafty attorney could argue that a ban on carrying weapons outside the home during a time of declared emergency serves a "compelling government interest" in preventing looting. If the tailoring of the ordinance is expected to be narrower, he could say, "well, just during a really bad snow storm" or "when the electricity is expected to be out for more than twelve hours."
It all depends. Anyone know where the 4th Circuit generally stands on 2nd Amendment issues?