Yes, but ... why would you do it? If you consider this because it is your first stage and you have heard that it is so difficult, there are also other solutions. For example: take a rest day first, or walk the stage in two days, or first walk some days in France, e.g. from Saint-Palais or Lourdes to Saint-Jean.
Read more > crossing the Pyrenees
By the way: after Roncesvalles there is another strenous stage, including a steep descent to Zubiri. We find it more demanding to descend than to climb. Why would you start with a difficult descent?
In addition to that: the crossing of the Pyrenees is one of the most beautiful stages of the whole Camino! (if you have some luck with the weather).
Finally: when you arrive in Santiago and you know within yourself that you have done everything on your own, that you have overcome all obstacles yourself ... wow, that's a fantastic feeling.
If you decide to have your backpack transported: Express Bourricot runs daily from Saint-Jean to Roncesvalles. "Express Bourricot" is run by Caroline, who also speaks English. You can call her (tel. (0033) (0) 6 61 96 04 76) or mail.