I used to do fruit and vege prep as a job - washed don't keep anywhere near as long - they need to be stored in the dark - as should unwashed - the difference is that the dirt does prevent them from greening as fast. I think the dirt also helps maintain the moisture level in the potato too - as washed tend to shrivel and go soft faster.
Never heard of anyone freezer potatoes though - in my experience they go very soft and squishy after being defrosted.

One thing I do know, there is no smell like a bag of rotten potatoes and there is nothing like sticking your finger in a rotten one either! EWWW!!!!