So I wrapped up well and made my way rather slowly up to Oxstones.
Near the stones the snow was quite deep and relatively undisturbed which made the final bit of ascent tiring. Even downhill along the pavement was slow as the path was slippery. Near the school I slipped on compacted snow and ripped a small hole in my overtrousers (and my skin).
I'm pleased I made the effort to go out and being 30% slower was probably what I should have expected!