All of the points above are good and valid. I’d like to bring up one more point considering the use of glycol. In Eureka, we don’t need to worry much about freezing.
However, our water treatment consultant told us that it’s also important to maintain glycol levels to stunt the growth of biological contaminants in the water. And, we’ve definitely seen a difference when our levels get too low.
You may want to consult with your water treatment specialist before getting rid of the glycol completely.