Following our East Midlands trip it became apparent that regular daily mileages of +80 miles was a bit ambitious. Cycling in a group it only takes a couple of punctures (or a spell of getting lost!) to make an 80 mile day a desperate race against the clock. I have therefore revised the itinerary to include 3 rest days (highlighted in yellow on this Google sheet).
On two of the rest days we'll do nothing, on one we'll take it easy with a 30 mile section. I've also reduced the mileages so that there are only 2 days (right at the end of the trip!) when mileages exceed 80 miles. There are some parts of Spain where it's pretty bare and barren and hunting down campsites wasn't easy, but I have managed to secure a place to stay every night now. I'm not going to book ahead, because the itinerary could change so easily. What we'll do is phone ahead once we're en-route, or just turn up - I've never been turned away from a campsite on a bike.