We reserved rooms all the way, but only did it a day in advance. There were never any problems. However, that was in May. In summer, you’ll be competing with the beach tourists, so I would suggest reserving a few days in advance. However, you probably don’t want to reserve too much in advance because then you’re locked in, and s—t happens. Also, if you use booking.com (for example) and you try to make reservations months in advance, they’ll tell you that there’s no availability, when, in fact, places don’t release rooms to the booking sites that far in advance. Another tip: the more inexpensive places, like pensions, don’t list on booking.com at all, and you can reserve them best with a phoe call or an email. These places are often listed on gronze.com or in the Wiise Pilgrim / Wisely apps.