Ah sleeping bags (or not) and ratings .... this thread could go on for a while! I agree with freescot, Two main problems with choosing a bag for the Camino - you cannot predict the weather; Spring could be warm and bright or snow to past Logrono! - then there are some high places to climb to stay where it will be much colder than down at low level.
So the rating of your bag should be weighed against the size and weight of the bag. Is 15C ok? - well, is it ok for you? How will it be if it is really hot? does it open at the foot? How will it be if it is a late winter and no heating in the refugio?
Also - men and women feel the cold differently. For cold weather females should get a bag that is rated 3 to 4C lower than one chosen by a male.
In the UK Snugpak make items for the military and the same items are sold - sometimes in other colours - to the public, globally.
They make and sell the Snugpak Jungle Light. It is rectangular and opens out completely so can be used as a throw. It has a mosquito net hood facility - no bed bugs then, as long as you only put it on your bunk when you get into it! and the inside is treated with an anti-bacterial anti-fungal preparation.
It weighs just 850 gms ! packs down
really small, though it does take some pushing and scrunching to get it back in the bag.
Obviously, as a 'jungle' bag it is fine for hot weather but also lists as comfort 7C and extreme 2C (don't depend on that too much, should it go below 5C you will most likely need to keep some clothes on!) - and - costs under £40. Under £40!!
It is what I now use - I like it, I like it very much. (I also have their Sleeka Force 35 rucksack - both in olive).
This is an honest youtube review. I agree with the chap about the zip on the mosquito hood but have never had a problem with it myself.
View attachment 6824
Buen Camino!