An inch bigger doesn't sound bad, got a fit pic? Personally like a looser, slouchy fit on cardigans.
You can always attempt to shrink it down a bit if that one inch difference really irritates you.
SNS doesn't really lend itself to slouchy fit- just not how it's knit? cut? Just looks like I'm wearing my father's cardigan. I guess it just really irritates me that it was advertised as one set of measurements, but the actual measurements are... not those.