Storage has varied, as we built more/better places. Currently we have a “sort of” root cellar; the NW corner of the barn foundation is closed off, and the interior walls and ceiling are insulated, the foundation is below ground in that corner. It takes longer than I would like to get cool in the fall (am working on that) but seems to hold its temps at 38-40F pretty well. The humidity levels are lower than ideal due to our dry climate and the concrete walls/floor. But it seems to work OK. Prior to that, we used a “cold room” in the house (heat turned off in it and door shut), and extra fridges in the garage. Even tried buried pits outside. Root cellar seems to work as well as any of the solutions and better than quite a few; I am hoping for storage improvement if I can get the fall temps lower more quickly.
BTW, I just started my Ailsa Craig seeds a week or so ago. The pattern which seem to work here is starting them Feb 1, transplanting when about 1 month old to the greenhouse, then transplanting again outdoors in April when they have sized up to “pencil” diameter and after most of our winter.