I don't agree with Wormtail escaping right at this time. Part of it is that I don't understand the purpose quite yet of this new development. The more substantial reason for my disagreement is that they are five. How can Neville face Voldemort if he can't even be trusted to fly a broom on his own yet? He and Harry? It's too soon. They haven't even boarded the train yet. There's not been any Quirrel yet, nor a cursed diary or a Chamber of Secrets to defeat. How is this going to go for our boys? In Canon, Harry was carefully prepared year by year and while the tests were dangerous, they were never so much that he couldn't handle them. If Pettigrew finds Voldemort in this universe as quickly as he did last time, they are so screwed.
.....Although I suppose he could do what he did previous and find the Weasleys to hide out in. Meanwhile, Harry and Neville are scewed anyway because as long as Wormtail is at large, they will have to be locked up.