I have always assumed that I could just kick the window to break it open in a situation like this.
(There was actually another HN thread about this recently - https://news.ycombinator.com/item?id=39691780).
I keep a Resqme in the car glovebox - my other half used to do a lot of interstate driving, and I was always worried she'd be trapped in the car. The Resqme has both a seat-belt cutter, and also a centre-punch for easily breaking the side windows.
Although a tiny piece of ceramic at just the right speed will shatter any window.
And I recommend a spring-loaded window breaker, as opposed to having to, like, physically hit the thing against the window.