I think to store them they need to be cured really well. I don't know how critical 75 degrees is but warm and with decent air circulation works for me. I probably cure mine at least three weeks out of the sun and in the dry. I made a frame out of 1/2" hardware cloth and 2x4's that I dry them and other things like onions on. I also use this frame to sift compost. These are Beauregards curing in my workshop sitting on 2x4's to get air circulation underneath.
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I used to get plants from Steele's in Tennessee and was happy with the but started to sprout my own.
I stored them in my attached garage. If they ever freeze you've lost them, they rot. The coldest it got in that garage was probably the upper 50's with the 60's more common in winter. When the weather warmed up probably the upper 70's maybe lower 80's. We'd still be eating them the following April or May before they went bad. I think they store better kind of cool but not to cold and definitely dry.
This is one thing I will not be able to grow after the move. The climate is great but the backyard is way too small.