I don't worry about the weather, but I do run 20% oil in my glo versions.
A comment, if your CDI is a kit conversion then keep running 20 % oil, if it is a proper 170 CDI then you can use lower oil,
these 2 engines are not the same internally, they have differant cranks, conrods, cam follers, carb housing.
A simple way to tell is to look at the cam followers, if they don't have spiral groves around them then it is a kit build,
and the carb housing don't have a bleed screw on it.