Well we went out and did it. We bought a tent. Now we are planning our trip.
Here is the tent that we got Pebble Creek™ 10 Person Tent it can be found at http://www.colemanc anada.ca/ Catalog/TENTS. 7_to_10_Person. en.products it is bigger then I thought it would be but with 3 growing children I know that we will need the extra space soon.
I think that we will go to Drumheller for a couple of nights and then up to the Rockies for a day or 2. Later in the summer we will probably go to Calgary with the kids.