You need to bring a Hi-Vis vest with you that conforms to the appropriate European standard. It is a legal requirement to wear one of these outside of towns at night and in poor light.
We don’t normally cycle at night in France but, if we encounter poor visibility, eg fog, mist or torrential rain then we must don these vests. That said, in such conditions, we’d probably try to find some shelter or sit in a café for a while.
Hi-Vis vests are readily obtainable and quite cheap, eg at Halfords.