Portugal, Sicily. Where will you use it? Leave it outside your tent while you roam around the island and use it in the evening?
Have a cup of coffee and place it into the sun and then the phone is charged after half an hour?
Question is can you leave it some place unattended in the sun all day long? How fast will it charge?
How long does it take until the solar panel completely charged the battery? How long until that battery needs to charge your phone?
If you are really away from the grid for long times solar might be worth looking at. If not an external power bank which you charge from the grid might be the better solution.
Mine is powerful enough for 3 complete recharges, takes about 2.5 hours to charge the phone, maybe 5 hours to charge the power bank.