I don't think we should be going to Leeds at all, regardless of whether any stadium there has been revamped or not. We need to be moving away from Leeds and into other areas. London is vital for internationals I think and given Manchester's status these days so too is that city. While we have the Grand Final at Old Trafford, City's ground could become our international venue there. A third test venue could be more mobile, maybe taking a game somewhere totally new, perhaps where an amateur or lower league club is based in the midlands or south of the country, or maybe just to a Superleague club's stadium to give the sport a direct boost.
I agree I'd love us to take England games to different cities. Manchester and Newcastle would be the next most likely, but I'd love to try Birmingham and Liverpool as well.