I walked the Francés in July?Aug of 2007 ad 2008 and had two completely different experiences. The first, in 2007 I did exactly what Sil said - got up early, didn't stay in large towns or large albergues and never had a problem finding a place to stay. I usually began walking between 6 and 7 in the morning and continued until between 14h and 17h depending on the weather, how tired I was, the terrain, etc. It was very pleasant.
In 2008, I fell in with a group who really wanted to stayin the larger towns. Since it was my second Camino, I decided beforehand to do it differently: walk alternative routes, stay in different towns and albergues than the previous year, so I was not too disturbed by their plans. We generally began walking later and while we usually walked between 20-27 km per day, we stayed primarily in large towns. It was quite challenging to get a bed. As you sat for a coffee and so many people around you were "making the call" to reserve a bed, it was hard not to fall into the same trap. Since I was walking with a young couple and the girl was not an avid walker, her boyfriend was very concerned that she enjoy the Camino and didn't want them (us) to be without a place. I thoroughly enjoyed their company (and I think they, mine) so I just accepted it as another mystery of the Camino - a different way to do it.
So, you can do the Francés the way Sil said, or as Omar mentioned you could choose another route. It all depends on what you are seeking from your Camino. Whatever you choose,