Is there maybe a park and ride lot or a train station or giant store that doesn't care in between you, on the way to City, where you could meet, go together, return there, and each go home? I can see wanting to go together to and from the concert -- parking alone will cost a lot, and it would be fun to have the chance to talk. But the way she is proposing is not convenient and doesn't sound like fun. If you live in Utopia, where public transporation works, you could perhaps train or bus to the venue and bring picnics for the ride. Sometimes there are special event buses from park and ride locations for huge concerts and sporting events in Big Cities. There simply has to be a better way than what she proposes, and I suggest a little web work might make one apparent. What everyone else has said about saying you can't spend the weekend with her is all very good and quite polite!
