How great, Beatrice!
Being on the ground in Santiago, here's what I've been hearing the past few weeks from pilgrims arriving from different routes: the Via de la Plata is already getting hot, hot, hot. In July and August it will most likely be even hotter. And with the sun bearing down and very few parts with shade, it's probably not recommended for the time you'll be on the trail.
Nate just did two weeks of the Camino del Norte from Irún to Santander and loved it. There was sea on one side and mountains on the other for much of this section, and some days he was literally walking on a beach to get to the ferry which would take him to the town with the albergue (sounds so fun!). The one downside was there was more pavement walking than he thought there would be. Other pilgrims who've walked the Norte say it's challenging, there are plenty of pilgrims around but it's not crowded, and it's a gorgeous walk.
A few pilgrims who have recently completed the Camino Portugués from Lisbon have said they enjoyed the section from Porto to Santiago, but they just slogged through Lisbon to Porto. It was unseasonably warm recently, though, and they said that section contained a lot of highway walking.
So that's a snapshot of what I've been hearing. Of course, other pilgrims who've actually done the walks recently can give you even more information.
Have you considered walking from Le Puy? Or the Tour de Mont Blanc in France? I've heard that's incredible!
Take care and have fun planning, wherever you end up.
Faith