I would not advise booking very long in advance, with the clear exception of SJPP (because if you start there, then the nights you'll be there are 100% predictable, and it's often very crowded there too) and the possible exception of Roncesvalles, as by booking far in advance for locations down the road, you may unwittingly lock yourself into a certain pace for the Way which might very well not correspond to a more natural pace developed over the first days and weeks.
So you might end up even "breaking" the continuous walk that's the ideal from a self-imposed need to maybe grab a bus or taxi, when that might otherwise have been unnecessary.
I'm not personally keen on the idea of booking ahead at all, but for those who prefer to do so -- and for some people it might be a real necessity -- my impression from the experiences and practice of others is that it's really only in the most extreme crowded conditions that booking more than 24H in advance might be a useful tactic (and usually a call in the morning of the same day is sufficient) ; unless you're part of one of the larger groups or "Camino families" walking together and so needing to ensure multiple reservations simultaneously.