Car Barge -
There's really no way to predict whether all will go smoothly or not on the day of your arrival. Sometimes, it's fine and other times there are long delays. Make your reservation.
Call to ask what happens if you make a reservation and things are backed up. Do they honor the reservation timeframe?
What happens if you're late?
Give yourself plenty of time on your end as planes can be late, traffic can be bad, etc.
Don't stress about it. You'll get where your going, sooner or later.