Success!!!
We just arrived in BC yesterday. On two iPads, we inserted the Rogers SIM cards I got from The Apple store last month. We had already attached them to iTunes to initialize them. Once we arrived into Canada, we entered a Canadian mailing address of a friend, and we both used different US credit cards. We activated OK and I am posting this from my iPad while in Canada.
/Jim
We are back in the US now. Both of our iPads worked flawlessly during the 7 day trip. We each used about 600 MB of data.
At the border on the way home, we switched back to our A&TT SIM cards and we connected right away to the AT&T network.
It looks like I am all set now for my somewhat frequent trips to Canada.
/Jim