The key is to get it cooled properly in the first place.
If you get the hide off relatively soon after it's down, and it gets a good night of cool weather ( near freezing like we have now )
Then the chill should get to the bone..
After that, you'll have several days grace in an insulated garage even if the day highs reach 12-15. As long as it cools at night it will stay cool.
Try to avoid opening the doors during the day...check once during the day if your concerned. the back of your hand will tell you if it's staying nice and cool.
I know some will say wrong!! and that it can't go above 5 deg...
I've lived this exact scenario numerous times over the last 20 years because I live nowhere near a hanging cooler and I've never had one spoil or taste bad because of bacteria growth?
Saying that, there has been times when it just didn't cool enough at night for it to keep cool so I've cut them before it was ideal.
Just need to pay attention to it and act when you think you have to.
Have you killed it yet?
Maybe your worrying for nothing...