Using migration assistant to transfer data via WiFi and after 20 hours got WiFi got disconnected

Got a new MacBook Pro and I’m transferring data from old Mac using WiFi. At the beginning said 25 hours. Thought was excessive but after reading some posts learned that was normal if I was doing it over WiFi (my mistake...) For the last couple of hours got super slow, the timer hasn’t moved at all!!!! And I’m afraid is gonna disconnect at any point or the WiFi is gonna fail on me . What should I do if this happens. Is all lost???