The theory being that if my US accounts got temporarily frozen for whatever reason, there's some chance my canadian account would be OK. Then I could use this as an ACH hub to move money between investment accounts and paying off credit card bills, while my US accounts are getting unfrozen.
Imagine there's a run on paper currency in US banks. I have my T-Bills that are safe, but no way to get them, because if I ACH them to a US bank, that bank might "steal" my money, at least in the short term, to meet their other obligations. By having a Canadian bank account, I may be able to ACH T-Bill sales into that account.
It seems like most of the situations where the Canadian bank account would be useful are fairly unlikely, however the opportunity cost of me keeping $1000 in there is virtually nothing, so if it's not a big deal to open the account, I might as well.
On a further note, if it was possible to get a safe deposit box, it would seem reasonable to keep 10% to 20% of your gold holdings in coins in the Canadian bank. We can be pretty sure Canada has good laws to protect your bank box, and it's possible to drive there. So if there's some restriction on gold ownership in the future, and we kept our gold coins offshore in a non-drivable country, then it would be hard to get them onto an airplane. Unless we're willing to drive through Mexico into Central and South America, Canada is really the only option here.
I know the US requires financial disclosure of accounts exceeding $10k internationally. That means I could keep $1000 in cash in the account, and 180 ounces of gold without having to report it. Remember, 1 ounce US Eagles are only worth $50 each as currency.

I imagine the answer is "no" I can't open a Canadian bank account, thanks to the US government protecting us from terrorists and imposing international financial restrictions.