I don't think the track width limits the numbers in a heat, it's so long that they all spread out anyway. And I'm all for more heats with less cars in them.
I'm more of the thinking that it needs to be wider so you can go offline without going into or over a track marker.
I've posted a blog entry about my visit:
http://rclazy.com/2010/03/16/torch-t...oad-car-hants/