I believe that the parking meters along the streets only charge on weekdays, so anywhere that there are meters should be fine. I can double check on that, though.
Update: According to cityofvancouver.us ...
"All parking meters are enforced from 8 a.m. to 6 p.m. Monday – Friday, except for the following holidays: New Year’s Day, Martin Luther King’s Birthday, Presidents’ Day, Memorial Day, Independence Day, Labor Day, Columbus Day, Veterans; Day, Thanksgiving Day and Christmas Day."
Also, "Disclaimer: The information contained in this document is subject to change. If you have a specific question, please contact Customer Service at (360) 487-8454 or Parking Services at (360) 487-8650."
I also just called the hotel and, according to the operator, the parking garage is $2.50 from 6am-10pm on the weekends, or $0.75 an hour. (So, if you're planning on staying for more than 3 hours, you should pay for all day). They accept cash or credit card. (I probably should have asked if that includes debit card...)