Doesn't seem planned. He would have emptied his bank account before leaving on the trip. Also he wouldn't be driving around for several days in a known car with known license plates. It could have been planned much better, but that assumes he is smart and logical.
Smart and logical people don't kill their defenseless girlfriend - in a rage, premeditated, or otherwise. So that's the hard part - trying to figure out how someone like this really thinks.
It's like we should be asking other convicted murderers what they would be doing in his situation. I can't even imagine being in this situation, so even though I have a lot of ideas about what this guy is doing now, he's probably doing something way different.
He's obviously sick in the head. Anyone here able to think like a narcissistic crazy woman killer? It could be helpful!