It's possible that Corbyn as a personality might win his own seat or even London Mayor (as Livingstone managed), but there seems little chance that it will generate a new radical left social democratic party.
First, because of Corbyn's own personal failings and ineffectiveness.
Second, as a general weakness of the social democratic (and Leninist) left, any such movement quickly falls into leader-worship (see everything from Gerry 'rapist' Healy to Tommy 'grass' Sheridan). With the leadership-principle in place, improvements cannot be made and the organisation is quickly corrupt. Decisions are made on how far it forwards the ambitions of the Great Man. Thus, the new party is regarded, rightly, with the same suspicion as all the other political parties that act on the exact same principle.
Third, because if it had even the slightest chance of making headway it would attract all the left-wing parasites that have sucked the life of so many marginally-effectively oppositional movements in the past. From grifters to nutters. To deal with them you'd even need a tightly-disciplined organisation of control (like the SWP, WRP, CP) and hence limit support and participation and gain a reputation for authoritarianism or else if more democratic and open, it become tainted by the conspiracy nuts. Easy meat for the corporate media and standard parties to attack on.
Fourth, because even with Corbyn and one or two of his last few Labour MP supporters (who would have to defect), the new party would lack the most basic material resources to actively compete as an electoral force.
So even if Corbyn pulled off a few electoral heroics, there would be little to threaten the Starmer's Labour Party.
In my life time all semi-effective opposition in the UK has come from outside electoral politics: fighting unions, anti-poll tax campaigns, anti-roads direct action, anti-capitalist demos. They've certainly been more fun than my brief (but still too long) time in left-electoralism.