There is usually a wave of short-walker pilgrims who start at Sarria on Friday, Saturday or Sunday mornings. They have a five-day walk into Santiago. While the new process at the Pilgrim Office quickly handles most any number of daily arrivals, the
Camino Frances route from Sarria to Santiago can get VERY busy.
This 'wave" of new pilgrims coming out of Sarria, walking towards Santiago each weekend, will act to saturate the available cafes, restaurants and accommodations at the five major stopping places on this part of the
Camino Frances. However - and this is key - this varies by day of week and month of the year. I call it the "pig in the python' affect.
In the autumn or winter I would not worry about crowds at all - anywhere. The bigger problem would be finding places to eat or sleep that are open.
But from Easter through mid September. There are usually waves of just starting pilgrims coming out of all the starting points on the weekends, along all the Caminos. You need to think about this pattern, and plan your travels accordingly - unless you are one of those people wio loves crowds.
Hope this helps.
Tom