KCM is solidly intermediate, and I don't think she's ever put out what one would call an advanced workout. Even her more challenging premixes, I don't think could be called advanced, either.
That's being said, she has a (short) Cardio only premix from
Plateau Buster that come to mind(which doubles up the cardio moves from both workouts). It's only about 30 mins., so, while I'm not sure what length you're looking for, if you're interested in longer workouts, that may not interest you.
I can't speak, personally, to level or intensity as I've never done the premix. I just only ever do her combined workouts premixes and call it a day
BUT those cardio moves feel pretty challenging while I'm doing the complete workout. I imagine they would provide for a challenging workout when strung together. (I REALLY like the cardio moves in that one.)
ETA: I think you could make good use of
Bootcamp. It's not straight cardio (she does use weights), but rather, metabolic, which is certainly cardiovascular. Not advanced, but maybe higher intermediate.
And, I concur with Sabine -- the cardio only premix from
Shape Up must be a killer workout; THAT one, I bet, would feel advanced!