Re. public holiday, this weekend is the public holiday. Crowds today (and yesterday) have been crazy, and I'm going nowhere near the mountain tomorrow (half price tickets, gonna be busy!). But as I read it the OP gets here Thursday, i.e. next weekend. Shouldn't be as bad.
Totally forgot they were doing the half priced tickets so yes, tomorrow will be stupid busy. We rode down to the gondola at like 10:30am/11am because it was getting pretty busy and the Whistler gondola line up was FULL had to be a few hundred people waiting to line up. Funny thing was Fitz chair, which is right beside the Gondola had NO ONE lined up, I just shook my head and walked off laughing