As far as the Triple Crown, you may have to go to Plan "B".
I am pretty sure there are some Canadian folks on this forum. Hopefully they can give you some top name brands of feeds to look into.
In the meantime (waiting for some of our Northern friends to come in:), if you Google "Canadian Horse Feeds", you will get some hits to look into.
If the Triple Crown 30% is what you were going with, try to find a ration balancer in Canada that has the closest possible ingredients. It might be a long shot but, Triple Crown may even be able to help you cross-reference their 30% to something similar in Canada.
Paying for shipping even 50 lbs of feed across the the U.S. border would most likely be astronomical and not at all cost-effective. Writing that check would grow old quick
As far as supplements, you may have to do that thru a veterinary catalog like United Vet Equine or Valley Vet. I'm betting the Canadian folks will have a better answer for that, too
In the meantime, you could always call UVE and Valley Vets' 800 numbers to see if they can ship to Canada.
I should own stock in both these companies - meaning I know they are very reputable, ethical, great to do business with and ship on time United Vet Equine - horse supplies, equine supplies, horse nutrition, horse supplements, horse vaccines
I just spent over $300 with Valley Vet for medical supplies for my horse with the torn ligaments and sesamoiditis. I bought large quantities - his recovery (thus poulticing/wrapping will probably take until Armageddon gets here
The shipment actually arrived faster than I expected Horse Supplies, Pet Supplies, Farm Supplies, Goat Supplies - Valley Vet Supply