Hello Sheila,
Having walked from Leon, you know what pilgrimage is about.
One of the first big questions pilgrims ask upon meeting each other is " Where did you begin? How was your first day on the route Napoleon from St. Jean Pied du Port?" Everyone compares horror stories, and believes they achieved the impossible that day. It is a great topic of conversation.
That said, I began in SJPP on April 8, and because snow was forecast, I took the recommended route through Valcarlos so I cannot proudly shout "I conquered the route Napoleon".
You know your fitness level, and your inner strength, so the decision is yours.
There is no "Official" starting place, and Pamplona is very convenient to get to by bus and train.
Whatever transpires, enjoy your journey.
And have the trip of your lifetime.
Buen Camino,
David, Victoria, Canada.