If however it is foggy, do the opposite. Drivers as a collective often take the speed limit as a suggestion at the best of times and are really bad at slowing down to appropriate speeds for the visibility.

I'd rather be crawling through a tiny village at 5MPH knowing that there are only a couple of cars around than at 50MPH without being able to see my stopping distance because I'm near guaranteed to be rear-ended otherwise.

And yes there was snow on the ground, but not a massive amount, and in the bit of the UK I was in, there isn't much distance between villages, so very very little risk of getting into serious trouble not in reach of other humans.