I went to one practice in Montreal and it made it such a long day that I needed lots of caffeine to enjoy the actual competition... So I skipped all the other practices . you are a trooper if you were able to do both. Such long days.
I know it's a bit late to respond to this, but no, I couldn't be a trooper on the 6:30 am practice day. I was up that early to see the Japanese guys and I don't think I had gotten much sleep (if any) after arriving in Montreal the previous evening. I left after a few hours, even though the guys were still practicing at that time (I think), due to how tired I was. The freezing wind outside the arena was surprisingly refreshing and I decided to walk around Montreal for the remainder of the day.
For Montreal Worlds I did 16 hours+ almost every day (with lots of caffeine, of course) and I'll do it all over again, that's how much I loved it!
My friend, on the other hand, I don't think she will ever go with me to watch another competition!
There was at least one day where I split the practice and competition; I deliberately missed some of the rhythm dance so I could see the Japanese guys in the practice rink. But 16 hour days? I don't think I went that far.