Per longarekel.
I myself used to keep motza”sh per Rabbeinu Tam ‘bli neder’ but would often daven before that, just not do havdala or any melachos before that.
As of late I haven’t really been doing that very much since I live in a place where (almost) nobody does so and in summer in particular, honestly, I think it’s late enough already when shabbos is out at 11:15 PM or so!