A lot depends on fit. I have a 22 y.o. Appaloosa gelding who gets cold very easily. He spends much of his time in a 400 gm winter blanket, and when it’s windy or the temps drop into the -20 or colder range he wears a 300 gm liner under that, and he’s been comfortable in that. He doesn’t wear a hood. Both his liner and his blanket fit him fabulously, and are lightweight but very warm. He doesn’t get rubs or sensitive spots under 700 gm of fill. My suspicion, given some of his other issues, is that he’s PSSM2 positive, so warmth really matters to him, I’ve had to rug him in June at times.