I do not know the details of your flight, but I can say this. When I flew from Calgary to Auckland, my backpack did not make the flight to Auckland from Vancouver, where I changed planes. When I discovered that it had not arrived in Auckland, I asked if it would arrive the next day, as I had a day planned in Auckland, then an onward booking and connecting arrangements after that. It turned out that the next day was the only day of the week when there was no Vancouver to Auckland flight. Fortunately for me, a family member in Auckland was a hiker and willing to loan me his backpacking gear. I bought some basic clothing and continued on. When I returned to Auckland a month later, there was my backpack at the airport and the baggage control gave me a small amount of money to cover my clothing costs. So I had my personal gear and chosen clothing for my last week in New Zealand. Since your flights are on the same ticket, your booked baggage is likely to arrive in Santiago. If there is a second flight from Barcelona to Santiago the same day, your plans may not be too disturbed, as you can pick it up at the airport later in the day and go on. What my experience in Auckland has taught me is that I have only taken carry-on baggage ever since.