Lyft is another option along the lines of Uber. I know Uber X is geo-locked at the Domestic terminal, but Lyft is not. I've also found Lyft to generally be a bit cheaper, especially Lyft Plus compared to Uber XL.
Taking the SkyTrain to the Marriott Gateway is another easy way around the geo-lock of Uber X. I can't speak to the specifics of the International Terminal.