The OM states the first stage that comes with the Alpha 8 can withstand temps down to 50 degrees Fahrenheit. I am being told I should switch it out for temps below 70. I will be doing a mix of diving in warm ocean waters and some cold lakes. Is there a happy medium here? I want to use one set-up and not have to worry about switching components out. I don't see myself diving in waters below 60 degrees.