Unfortunately 45-48 "real" Republicans could be about the correct number, but there are far fewer "real" conservatives among those "real" Republicans (knock off another 10 at the very least) so it will be a long, long time before 51 votes are available.
(Guess this is as good a place as any for a first post):
The Republicans gave up nothing. We get our up or down vote and maintain the status quo sans Dem obstruction. We just allowed the Dems to save face by permitting them a facade of a victory. There is no substance to the "agreement" at all.
Someone please explain to me what we gave up. We got everything we want and gave zilch. The constitutional/nuclear option is still on the table the next time the Dems pull the filibuster crap on judicial picks.