Wow, I had not followed up on this thread after posting the respone I got back from HAL.
I thought I had explained the reasoning for the original question clearly but I guess not. I live in the Seattle area and found a crazy good deal on the San Diego to Vancouver cruise. It worked out better for my schedule to just get off the cruise when it stopped in Seattle rather than the next day in Vancouver so I thought I would see if it was possible, found out that it was not possible and decided we would just use Greyhound to get back from Vancouver.
Didn't matter in the end as we could not find anyone to watch the kids Monday night so we didn't end up taking the trip.