I'm doing my second Camino starting in Pamplona on Sep 3. Last time I went in May/June 2017 and carried a summer weight sleeping bag (55 degrees F, 1.6 lbs) and it worked great. I'm concerned that I need a different bag because it will be colder - I have an REI down bag that weighs less, but I can't get it compressed as much as the other. It's rated to about 40 degrees F, and weighs 2.2 lbs. Third choice, I have a down blanket (700 fill) that's big enough, weighs only 1.3 lbs and I can get that compressed very small (probably would take that with a liner). So, am I worrying needlessly? Am I likely to be cold in Sept to early October? Has anyone else used a down blanket instead of a sleeping bag? And, sorry, using an albergue blanket is not for me.