havent seen a 48 for sale (apart from when it was out).
measures like 53cm / 54cm across the chest pulled tight in a 44. 48 would be like a tent i reckon (dunno what sleeves would be like either as it's not a 'tight' fit).
i'm 6 foot also so not a shrimp (it's long also).
not trying to sell mine / or want to. but know how maddening in can be to buy something expensive that's wrong size.