IMO your best bet is to find US online retailers with good policies for shipping to Canada. I recently asked a very experienced Canadian homebrewer (who is also one of the country's top beer judges) about this. He told me he uses morebeer.com for specialty grains and equipment; freshops.com for leaf hops; hopsdirect.com for pellet hops. His club is able to bulk order base malts once per year. I wonder if The Brew Shop in Dartmouth would be into ordering base malts for you. Plan B might be to get in touch with whoever the folks are in this thread: http://www.ns4sale.com/buy-sell-swap-barter/10078-october-malt-order.html
Plan C maybe call Alexander Keith's and see if you can buy malt from them. Plan D find a maltster out east and give them a shout.
These guys are located in Toronto and carry almost everything you will need. I have had a few small issues with them in regards to shipping/order mix ups, but things have always been sorted out in the end.
Shipping is reasonable and you can pay via credit card or paypal. Milling is free if under 5lbs and they have been known to make exceptions
The only thing that really sucks is their website, but if you're like me you'll spend so much time browsing that it will become second nature in a mature of days.