Just as an FYI, if you have
John Brierley's
Guide to the Camino Frances, and if IIRC, somewhere in the introductory material in front, there is a mention of how his 33 stages came about. Simply put, it is a subjective value based on the number of years Jesus Christ was said to have lived on earth.
From this, everything else fell into place. Over the years, this one guide has caused these 33 stages to become more or less, carved in stone. Most everyone accepts this as THE STANDARD outline for doing the
Camino Frances.
However, this is just one construct. You can choose to do the
Camino Frances as fast or as slow as you choose. On my first go in 2013, it took me 36 days, as I had injuries that required a three day stay at Burgos. Many folks from Europe take several yeas to do it in segments as they can more easily travel to and from the nodal points (SJPdP, Pamplona Logrono, Burgos, Leon, Astorga and Sarria) by train and or bus.
On my second go, in 2014, I intentionally stretched it to 40 days. This was predicated on wanting to add rest days at places I just blew through the first time "to keep on schedule," and to walk shorter daily stages. it was a far more relaxed and more productive Camino, IMHO.
My advice is to plan for SIX weeks, 42 days. Spend two nights at St, Jean Pied de Port before you start walking. Plan an extra "rest" day at Burgos, Leon, Astorga, and perhaps Sarria.
Plan to spend the remainder of the 42 days (3 - 4 days left) at Santiago de Compostela (SCQ airport code). I believe you will be happy that you did. Also, if you stake this longer plan out when you make air reservations, then work backwards from SCQ, you can adjust your daily travels as needed to arrive 'on time.'
Most of us traveling to France or Spain from off the European continent (AUS, NZ, US, CN, etc.) have to spend a lot of money, time and effort just to get to our starting point. My view is, what's the rush? You invested so much time and treasure to get there, you may as well make it enjoyable. Time is the most valuable commodity we have as humans. At the end, no amount of treasure will buy us another day, especially another day on Camino...
Heck, if you have more time than 42 days, you could plan to spend several days in Madrid or Lisbon on the way home. I have done this as well. Personally, I find that, after I've done a Camino, I am in NO RUSH to return home. Any activity I can find to spend more time in Spain or Portugal is worth the added expense, to me at least. Can't get enough!
Hope this helps.