I don't consider myself a 'fit' expert. Not sure if the 46 to 48 inches refers to your waist. Assuming it does I can say from my experience (I am 5 ft 4 in tall, weigh about 210, and have about a 42 to 44 inch waist) that the medium size I purchased for myself 'fits' with exception of being able to fully zip the snorkel hood. In hind sight I would have ordered a large. The jacket is very warm. I suspect you wouldn't need a light Cardigan. Just a shirt (I wear flannels) will do. In your case I am not sure if the extra 2 to 4 inches of girth would warrant going to an extra large. Keep in mind, the jacket has some weight to it. Not sure if the weight goes up appreciably when you go up in size (just something more to keep in mind).