Yes a few years back my Sheila did a tour of Tasmania like that - no GPS map to speak of but a fine collection of tracks generated from Gmaps.
In contrast to the blank areas in France, some places, notably the university towns, are astonishingly detailed. Look at Brest for example, or Bordeaux.
Another thing I found, while adding roads across vast blank areas, was that all the propertry boundaries were already in place on OSM, even though the roads weren't. Especially in the vineyard areas. Priorities!