If Christie, Kasich, and Fiorina drop out after NH, the only thing chipping away at the establishment vote is Jeb's remaining supporters, while the anti-establishment vote gets split almost 50/50 between Trump and Cruz. So let's hope Jeb's ego and connections keep this from turning into a 3-way race where the establishment candidate (Rubio) comes out on top.
Doubt Jeb will withdraw prior to Florida (Super Tuesday). He has the $$$ to stick around till then. His ego will not let him drop out till after the Florida primary.