Hertz - What's wrong with Ottawa?

Looking at trying to rent a car in Ottawa this weekend and not one of the locations seems to have even a single car available on a Saturday. That seems impossible to me, am I wrong? Is that normal that eight locations would all be completely sold out on a weekend four days before?

It is a major holiday in Canada this weekend (Victoria Day weekend), and many people rent cars to travel. They may be:

a) truly out of cars, or
b) have a minimum rental period of 2-3 days.

-Brian