I live in Stillorgan and regularly cycle to Enniskerry and beyond. I assume you go via Sandyford Crossroads, Stapaside, Kiltiernan. This road is parts of the Wicklow 200 sportive (see website) in early June each year.
I'm retired and cycle for exercise. I wear bib tights, cycling jersey and a rainjacket / gilet / windbreak. No panniers or luggage.
We had six inches of snow on 10th January 1982 and not much since, although you might get a little in Enniskerry.