Any dry seeds will survive indefinitely in a deep freeze or refrigerator freezer compartment. I store my seeds that way and have used seeds from the same supply for years.
If we are all forced to grow our own food, do you really think the power will stay on?
That being said, keeping seeds in a cool, dry spot, I’ve had them stay viable (or atleast 50-60% of them) for 3-4 years.