Good to hear you have the problem under control for now.
As for the potential head gasket problem, mine never really had the overheating problem in the winter either. I did manage to have it overheat once when I was pulling a trailer up a mountain. You may not see that symptom again until it warms up. I don't know if that's good news or bad news, but at least it gives you a chance to save up some money for the repairs.