I don't know how closely our climate in New Hampshire compares with BC but if there are any old cars here without rust, they almost surely came from somewhere else. I kept my TR3 stored in an unheated garage here in New Hampshire for 30 years. Although it did show some rust beginning when it was first put into storage, it continued to rust badly over that next 30 years. The garage had a concrete floor and and was dry but not insulated nor even air tight. Bare sheet metal scraps in the same garage were covered with surface rust the first winter. Certainly well painted surfaces would fare much better and since my car already had some rust started it might not have fared better in more climate controlled storage.
I now keep my cars in a well insulated garage which has heat but that is turned off when I'm away for long periods in the winter. I'm guessing that the insulation keeps the temperature swings to a minimum along with the associated moisture and condensation. I don't lift the tires, use battery maintainers or do anything else for storage.
The only problem I've had so far (fourth winter) was when I inadvertently left a garage window open for several days in the very early spring in with nighttime temperatures well below freezing and got a nasty mold on the seats of my old Buick, which was right under the window..
I do run a de-humidifier in the summer. My supply of sheet metal (which serves as my canary) stays bright.
For what it's worth, I recently visited an climate controlled auto storage facility nearby and it was pretty well packed with cars literally inches apart.