I have been upgraded on Radisson SAS many times. Mye experiance is that this is not dependent on your *G status only, but if you are a regular *G on the hotels.
Normally when I have been upgraded on a Radisson SAS, I have had many stays at that specific hotel.
Asking for upgrade on a Radisson SAS hotel, where you are not a regular customer, rearly works, at least for me.