As a general thing, what are we actually trying to accomplish by idling in the garage?
I like to take a reasonably long drive (so engine reaches normal operating temperature) before shutting it down permanently for the season. I can’t think of any benefit to starting a carbureted engine periodically, or any engine really, as the coolant temperature isn’t a reflection of oil temperature. I want all the bad stuff boiled off, or near enough. I tend to think no load idling might introduce more internal engine condensation, not less, as well as fuel contamination in the crankcase.
Sometimes people mention they do this “every two weeks” business to keep the battery charged. I think a better approach to that is to use a battery maintainer or “float” charger. Discharged or even weak batteries will freeze. Bad stuff happens. I turn my Y-Block engine over manually at the damper with a socket wrench every couple weeks, or when the spirit moves me, to keep things moving. I also pump the brakes &c. I guess Barners have similar OCD afflictions! A better approach there would be to relax the rockers so all the valves are closed. I’m not that OCD.