Calais to Portimao route idea suggestions help advice

[coleclough]

The Son and I are going to drive to the the Portimao track taking 3 days each way .This for the October meeting.
I intend to spend as little time as possible on the auto-routes.
We will start at Calais.
Any suggestions, ideas, "don't go there" etc would be more than just a bit welcome

Thanks
Jeremy