Dog for prepping purposes

Hello all;

I'd like to raise two points before I begin:

1. I wasn't sure where to put this thread

2. I am aware there is a search function. I find it terribly cumbersome.

That being said, let's begin. The wife and I are looking to add another dog to our family. This dog isn't a 'prep' per se; he will be a full fledged member. However, I'd like to solicit opinions on which breeds might be better suited to holding their own in a disaster scenario. My current dog is a dachshund, and while he is a fine creature in many ways, I would never entrust my life to him.

The ideal dog would be:

Large and fierce enough to hold his own against an unarmed assailant, or provide an adequate deterrent.

Calm enough to live in a household during normal times, i.e. not during a disaster

Able to survive on very little food

Able to walk long distances, endure physical hardship, and generally be a hardy beast.

It is possible no breed meets all these conditions. However, your opinions are still welcome.

Thank you.

Dog for prepping purposes