To echo many posts...Mogs are not just for summer!!
They are modern cars. Their ability to withstand corrosion is as good, if not better, than many traditional cars.
If there is salt on the road make sure you regularly wash underneath as well as on top. But otherwise drive it as normal.
There is magic in driving an open car on a cold and frosty day and a cold and frosty night is even better. I have a heated waistcoat: with the heater on and a hat and gloves it is warm enough hood down.
I simply can't understand why anyone would want to cocoon a Mog for the winter. Garage it, yes. De-humidify the garage if needed. But put it in prison? NO!
If you are really concerned about winter traction fit mud and snow tyres.