The whole idea that Saints would consider moving to a new ground is totally ridiculous IMO.
Think about it....Medium sized football club moves to lovely new stadium, the envy of half the clubs in the land, great facility's for matchdays / corporate stuff, good city centre(ish) location, less than 10 years old. Why on earth would the club risk getting into massive debt (and it would be MASSIVE, SMS was built for an absolute STEEL when you look at stadium construction costs in the last 10 years) and alienating some of the fan base by building a ****ty out of town stadium in a **** location? I mean, look at SMS, can you imagine bulldozers coming and knocking THIS down!?
You are deluding yourselves if you think the club would go down that route. Even expanding SMS is a pipe dream.