I walked through June, and finished in Snatiago at the beginning of July, and had no problems getting accommodation. As the numbers have grown, so too have the available beds. If you walk in July and August, or around the time of the various May public holidays, you can probably expect demand to outstrip supply.
There don't tend to be 'public toilets' in Spain: you use the local bars, which are very common. I didn't see much toilet paper adorning the route.
I did get myself a bit hyper-ventilated by the numbers walking between Sarria and Portomarin, but I guess that's what happens close to Santiago....
Margaret