La vuelta a Espanya

 Would be possible to have all the big tours in Zwift, Tour de France, Giro Wuelta a Espanya  or a short version of different stages

I imagine level design takes a long time, I doubt it would be possible to make the maps for entire tours.

Of course it is possible to do the whole tour, packing all stages into one string.

But without doubt it will take some time, though not impossible.