What MacBook can I buy with a M2 Extreme chip? There is no such thing. M2 Pro/Max is yet to be released. Only M2 is available or M1 Pro/Max.You can buy a MacBook Pro with M2 Extreme chip and have the same battery life.
On the go it's up to you if you use the M2 Extreme at the limit or not.
You can still use with the M2 Extreme the same amount of cores, which you are using now.
The M1 13” MBP is a great laptop. I know the new M2 13” MBP is in an odd spot but I still think there is a market for it. It would have been nice if Apple just put the 13.6” screen in it and I think it would have been more popular. Some people want more power than a passive cooled M2 but don’t need a larger Pro Model and want portability that the 13” pro delivers.