Due to the constraints of my time and my purse, probably no more than about 100 miles for me - but everyone will have different ideas about what's acceptable for them.
I will gladly travel for the right couple or single lady as long as we have known each over time.
For any newbie couple I would make sure we were going to the same club or place as so if either one of us decided not to turn up it wouldn't be necessary a problem.