Luggage Storage

My wife and I completed the Frances two years ago. This year we plan to do both the Norte and the Le Puy. Our plan is to stay in Europe for a year (with a Schengen long stay visa). Due to this long term stay we have to bring an extra suitcase with us (in addition to our backpacks) for the non Camino days. Any ideas how to send clothes ahead and store them in different places, including Santiago. I saw Ivar's posting with two links but could not find the information he was providing. I apologize ahead of time since I am sure this issue has already been discussed. I have searched but was not able to find the string. What assistance you can give will be appreciated.

Thank you very much MS. This was what I couldn't find.