D&O
No Mistral problems in Cannes.
In the South of France, there are two winds to worry about: the Mistral, which effects the Rhone valley (and which blows on average one day out of every three), and the Tramontane, which is actually the same wind as the Mistral but which blows through the gap between the Massif Central and the Pyrenees.
When they're both blowing, you don't want to be taking a sightseeing trip along the Mediterranean coast!
Don't have any info about tie-downs at Cannes. Sorry!