Hi, I've seen loads of people who have had trouble getting accommodation in this area. I looked at staying in Biarritz myself but found it far too expensive. I did however manage to find a really cool place, which is very affordable, just outside Hossegor which is about 30 mins north of Biarritz. It's a great place to be if you like surfing. I can give you the details if you want to know any more about it. E-mail me on firstname.lastname@example.org
if you want to know anymore.