I finally broke down and got an X-pen for the dogs. I ordered it from Costco.ca and it was delivered yesterday. It took me a long time to order it because I wasn't sure if the one on the Costco website would be big enough. It is perfect. Both dogs can easily fit and I think it is tall enough that they won't try to jump out. It should be perfect for taking to outdoor trials.
The only problem is, I don't think it will fit in my car :0