I am from the Netherlands and am planning to travel to Lisbon - Porto - Barcelona - Lyon - Utrecht. However, the interrail website doesn't make it easy to understand wheter (or not) I can book the seat reservations online.
The Lisbon → Porto train seems to be booked at the station, since these trains go regularly this should not be a problem.
We were also planning on traveling from Porto to Barcelona, on the 9th of July, going:
Porto Campanha → Vigo Guixar 8:13 → 11:35
Vigo Urzaiz → Madrid Chamartin 13:20 → 17:36
Madrid Puerto de Atocha → Barcelona-Sants 19:00 → 21:30.
In Vigo we could walk to the other station, in Madrid we should take the metro.
However, at the moment i cannot book these seat reservations online at interrail. Is that correct, as the website states it should be possible for the AVE, Euromed & Alvia trains?
If not, and i should book seat reservations at the counter, how hard is that in the summer? Are thes routes ever sold out?
Especially the first two trains are important to reach Barcelona from Porto in 1 day, and since we booked our hotels, the date is also quite important.
Can someone help me if it is correct i cannot reserve these seats online? And if so, how much of a problem this will be in July?