I could actually see Christie making quite a rebound if Trump lost. He has the qualities people liked in Trump ("tells it like it is") while avoiding the negatives (he comes across more articulate). Additionally, considering how little people talk about Bridgegate or whatever anymore (I literally can't remember the name, so there ya go! lol...), I doubt that bothers him much. I am not sure if Christie could beat an incumbent Hillary, though ... would totally depend on her four years.
He'd definitely run again.