The Lutonski road lies somewhere between Blaviken and Yspaden, so most likely cutting across parts of Redania. There are apparently a number of small villages along the route and winter weather is a problem.
|“||I'm making my way to Yspaden, but I don't know if I'll get there before the snows block the way. I might get stuck in one of the little towns on the Lutonski road.||”|
The Road appears on the map created for the 2nd Edition connecting Novigrad with Luton. It's a bit inconsistent with info from the short story, because the winters at the seaside tend to be rather mild which would suggest that travel shouldn't be that difficult in the winter.