Calais terrain test

I've been playing with my existing 6mm terrain trying to set out the revised table for Calais: The Road to St Omer.

Obviously there's a mismatch between the 1:300 scale of the models and the 1:4000 ground scale of the TacWWII rules. We instinctively understand the width of the roads and so we see the battlefield as a few hundred metres across rather than 3.6 kilometres. I'm giving serious thought to creating the road net in some other way for this game.

I have some tarmac roads made from cheap floor tiles (thanks Richard P for that tip) but they suffer from the same issue as regards overscale width.

Options, it seems to me, are:

1. Stick with the latex dirt roads,
2. Switch to the floor-tile tarmac roads (with the option of making some new sections that more perfectly fit the historical road layout),
3. Make a whole new tarmac road layout with narrower road sections for a slightly more map-like visual effect,
4. Create a dedicated 48"x28" gaming mat specifically for this scenario by airbrushing onto cloth, or 
5. Create a dedicated 48"x28"gaming mat specifically for this scenario with the canvas-caulk-sand-paint-flock approach.

I have until July to make my mind up and build the solution. Part of me wants to put on the best-looking game I can while the rest says that it's just a one-off event and doesn't justify the effort.

I shall ponder. Suggestions welcome!