You would be fine running to a sub-panel in the garage. You would have to account for the power draw of the a/c running while you are working in the shop.
You can run a sub-panel fed with a single double pole gfci breaker to protect multiple circuits.
I protected most of the house this way after a guy in my town was electrocuted vacuuming water in his basement.
I also have a detached garage protected this way.