Storing Race car for winter

In Pennsylvania when during the winter months I would just drain the radiator and fill back up with antifreeze. I let the electric water pump run while filling up and a little time afterwards to help circulate and mix the water and antifreeze. I would test the strength of the antifreeze than with one of those handheld testers. As long as it was like -10 or -20 or so I was good. Car was stored in a enclosed trailer and I never had an issue doing that for many years.