First draft... I can get this in KML, KMZ, GPX and some other file types for those who use satnav.
It says 505.15 KM or 11h driving... which means that it can be divided in two or three driving days, depending on how many miles you wish to cover.
Also some of the route might be adjusted as I included some sightseeing viewpoints.
I will try and do all the roads so I can confirm they are still Seven suitable... Besides the odd cobble stones towns, villages and hamlet "centres", I can only remember of about 16 km of rough tarmac in all but, the rewards are well worth it, IMHO. Anyway, I will always check the roads, closer to your trip.
Armadillo is in The Douro Valley and waiting for you.