Probably a dumb question, but have you attached it to the pad? Their 52", even 58", wide quilts can be super snug with the sides drawn together. I'm not a big guy, but extra width has always been a huge plus to me.
With this regular Flex 40, I've already found attaching it is necessary to avoid drafts, while just tucking the sides around me is usually enough with the 6' Wide Palisade, even way below its 30F rating(I sleep outrageously warm).
I'd have gotten the wide version of the Flex 40, even better a 6' Wide Chisos, but Katabatic is phasing out their 40F quilts as they use up the materials, so those options are no longer available
btw, it IS cozy! So silky, it's like being wrapped in a warm little cloud. I love the way the material feels.