Yeah, I'd definitely buy tickets in advance to be on the safe side. Did you see them at the Park back in April? I had to miss it because of school and I wonder how many people showed up. Honestly I'm a little surprised they're playing there because I figured Living With Lions had more fans in Winnipeg. But on the other hand, I saw them play the Cavern (which is basically the same sort of venue, except it has a stage) with Carpenter and Aspirations in November 2008 so maybe not much has changed. Only like 20 people showed up.
I don't know for sure either, but they might move it to a bigger venue if they sell out The Death Trap. Part of the problem is Winnipeg doesn't have a good all-ages venue for bands that size. The WECC is expensive to rent, I could see not wanting to commit unless they knew they could sell a certain number of tickets. Plus a lot of bands in their situation don't do well at the WECC anyway. The Flatliners booked that place out and it was depressingly empty. And the Park just isn't a good venue, plus I've heard stories about the owner ripping bands off. The Death Trap just opened a few months ago and it's already shaping up to be the best alternative it seems, even if it's tiny.