Hi Point Break,
I walked the Camino de Santiago in April of 2016 at the tender age of 64. I started at St Jean Pied de Port continuing to Roncesvalles, Pamplona, Burgos, Leòn, Ponferrada, Samos, Melide, Santiago de Campostela, Finisterre, Muxìa. It took me 40 days to cover slightly more than 900 km. I can only offer a couple of suggestions.
Travel Light : I only took one pair of pants, one t-shirt, one long-sleeve dry shirt, a hoodie, a windbreaker jacket, a watch-cap, two pairs of underwear, three pairs of socks, one pair of trainer shoes, one pair of leather sandals, a pair of flip-flops. and a towel. In a 40 lt backpack, with rain-cover, I also brought a light synthetic summer sleeping bag, a water bottle, and an increasing amount of medicines. I bought, along the way, safety-pins to dry out the socks on the stern of the backpack, a wide brim hat, and a couple of t-shirts.
Take Care Of Your Feet : After 20 km of walking, mostly on hard-packed dirt or asphalt roads, my feet hurt. After 25 km, my feet screamed to stop. After 30 km, I knew I was causing damage to them. I noticed that many of the persons wearing hiking boots were having problems with blisters. I was super careful to apply baby-cream and after 8 days I thought I was going to get through it without problems. Then wham, the ankle and knee tendons got inflamed. I remember after a lunch break, I got up and could barely walk heel-to-toe. Fortunately the pharmacies in Spain are allowed to sell effective anti-inflammatories (ibuprofeno) over the counter. The pharmacist was also very understanding and took the time to explain it while we worked on the translation.
Weather Window : Basically, you have to choose between mud and hot. I started on March 31 only to discover that the pass Napoleon used to invade Spain was legally closed due to snow until April 1 and possibly beyond that. The fine of 1000 euros for trespassing was more convincing than the receding snow; we walked the road. We got rained on and down-poured on, but it was never freezing cold. When the sun was out it was hot but not Dalì-melting-watch-hot. Mostly we walked through green farmland, lots of mud. We never had serious problems finding the cheaper 'municipal' hostels because the offer was more than the number of pilgrims and we walked relatively fast. I came to understand that in the summer, people would leave the hostel well before sunrise, in part to escape the heat, but also to be sure to get a place at the next first-come-first-served hostel. The last 100 km was more like a religious procession as this is the minimum distance for the 'credencial'.