I also expect to reach Los Arcos on day 10!It all depends how fast and far you walk in a day.
https://www.gronze.com/camino-frances will help you with stages. According to the stages on gronze, you could be be in Belorado, and the closest airport is Burgos.
If you walk as slow as us, you would get to Los Arcos...
And if you leave SJPdP any day between 4 and 11 May, you can come and see us at the Accueil des Pèlerins (39 rue de la Citadelle) in SJPdP, where we are volunteering.