HI I have done this several times, (at various times of the year) In a 7.5T lorry using both the east and west routes, I have to say the easiest route( if slightly longer) was definitely the western route down through, LE Havre Bordeax, San Sebastian, Madrid and across to Alicante This was almost all at a level drive, and motorway,, the other route I have used on occasion goes down via Toulouse, Perpignan and Barcelona, and involves quite a long trek uphill/downhill and at the time although it wasnt blocked the route was icy snowy and relative hazardous,