Hi Tim,
I had similar worries as "Fay" lives in a concrete unheated lockup about 5 miles from home.
When we first came back down here from herefordshire I had to put her in storage costing me £90 a month as I didn't have a garage as she would have had to live on the street, something I wasn't keen to do.
I bought an Airchamber from Hamiltons 7 years ago and she lives in there with 2 x 12v fans creating a through flow.
"Fay" has survived very well in this environment and sometimes when I go to see her during the winter when it is damp, often there is moisture on the outside of the airchamber, but inside she's nice a dry.
Couple of points against.
Although it has a fibreglass rod frame these are not thick enough to completely support it and it flops to one side or the other, not a bad problem but it can be annoying.
The latest version that Hamilton sell has a tubular frame that unlike the fibreglass rods are on the outside, and the chamber hangs to the tubular frame like the inner tent in a frame tent, only downside is that it is slightly bigger overall.
2nd Point is that as there isn't any power at the garage so I had to buy 2 x 85amp leisure batteries, and while one is running the fans, the second is on charge, once a week I go and change the batteries over and repeat the process.
If you have power available it isn't a problem as the fans are powered by their own transformer.
If using batteries they must be leisure batteries as they can take being completely discharged & be recharged with no damage.
Brian
8227