I would likely disregard Barcelona, since they'll be voting on whether or not to leave Spain tomorrow, and I don't think things will have cooled down enough for racers to go there by Monday.
Not sure if there'll be demonstrations/issues with the rest of Spain, but it's a politically tumultuous time in the country right now; I'd personally hesitate to consider Spain at all right now.
Even the rest of Spain is safe, the most particular cities to travel are either Alicante, Cordoba, Granada, Madrid, Malaga or Seville. Spain is probably sure to visit.
Sorry, I should have clarified better- what I meant by my uncertainty was more of logistical ease for filming in those areas.
I was just in Barcelona a couple of weeks ago and felt very safe the whole time.
BUT, I'm sure there are going to be plenty of marches, parades, demonstrations that will slow traffic flow, and make it difficult to reach- let alone film- at some locations.
And it could be the same for other parts of Spain- we don't know, this is going to be new territory for the country no matter how it turns out.