We have flights in and out of Madrid mid-July. We are traveling with teens. Was originally planning on training to Seville for four days and then returning to Madrid to spend four days there. Posts about the heat have made me re-think the trip and now I am planning to change to four days in Barcelona instead of Seville. Here are my questions:
Travel by plane: Our round trip flights from US to Madrid were booked weeks ago. If I now book a separate flight to Barcelona from Madrid, and our US flight is late enough to cause us to miss the connection, could our ticket still be used on a later flight?
Travel by train: I see a lot of talk about booking the train early from Madrid to Barcelona because it sells out. I am nervous about a possible flight delay and then our tickets would be worthless. Is it just the low fare that sells out or does the whole train actually sell out? I would not mind paying the higher fair that day so that we don't risk missing the train all together, but we need to be able to get on a train.