My info on this is from this time last year.
We (4) pilgrims were allowed to stay overnight in the monesterio. Forget about the described single luxury cells or food being available. They are booked months in advance by folks on retreat. We were greeted very kindly and shown to a large stone room where we slept on the floor. The two bars outside the walls were able to provide very simple food - salad, no meat or fish.
I really enjoyed staying there.