Couple things to consider -
One of those above-ground old school 200 gallon farm fuel tanks - the raised ones? you know what i mean?
Also
Your house isn't bullet proof. If it's wooden, consider finding a way to secure it - 5.56 goes through wood easily. And with sustained attack would penetrate most brick homes. Consider spreading your supplies in caches around the property and some with friends; include metal currency, sealed ammo, first aid, and...whatnot. maybe a spare pistol. Maybe look at a manual pump for your well. Can you secure your generators from theft? I dont need your answers but maybe things you can think about, if they help. Two is one, and one is none.