A year ago we bought a Miata from Seacoast Mazda. The manager lives in Alton Bay and his wife has a Miata. They winter it in one of the self storage units in Alton on Rt 11 just north of the bay. I don't know if there is still any availability.
My somewhat expensive solution was to buy an enclosed car hauler trailer and park it along side the garage for the winter. However, we also plan to trailer the Miata south in the fall so the trailer has dual use. We have heard about "The tail of the dragon"
