I'm staying at the Best Western City Center. $116/night US. It's about the cheapest I could find close enough to all events. I was seriously looking into the Hi-Ottawa Jail Hostel in town. That sounded like a great time, but I wanted a little more luxury and amenities.
I'm trying to see if I can get a friend in the chapter to go along. There's one guy that is thinking about it if he can talk his wife into letting him go - that way I can save half the cost of the room. I booked 2 rooms, a double and 2 queen just in case. Will cancel one.
The Best Western is about in the middle between the dealer and the air museum and the pavilion.
No availability at the Ramada and New Highway Inn has no 4 or 5 star reviews, mostly all 1 star reviews.
Rooms are going fast. I think you can find lots of $400 ~ $600 per night rooms though.
If you to rough it, try the jail.