Hi Stringfellow
I have 2 options; a reasonably cool garage and a shed. Sometimes, (like this winter so far), the shed is ideal but most winters the garage is ok. I have some large plastic containers that I have managed to accumulate and I stack these up with plywood inbetween. Carrots, parsnips, beets and swede all keep well using a mixture of sharp sand and old potting compost. The mixture should be only just moist. I have had a little bit of top growth and fibrous root re-growth, due to the mild conditions but it has not affected the quality so far.
Hope this helps
Pete