I had a thought and did a little research to support it. Most places, other then the desert, get more humid in the summer. My thought was that Montana summer dew point might be similar to your Georgia winter dew point. I did a search for "Montana dew point in June." I came up with weather information--and had to pick a city. Helena, Montana has average June dew point in the 50's. Here's the link: Average Weather For Helena, Montana, United States - WeatherSpark You can check other cities on that website.
So, you should be able to use what you've been doing under similar dew points.