Is that card available to Canadians?
It is, but since it's a U.S. card, it takes a fair bit of effort and time to get it, i.e., need to get yourself a U.S. domiciled bank account, a U.S. mailing address, an ITIN, and a start to your U.S. credit history. Americans are lucky with the number and quality of credit cards they have. But as a Canadian, if you are willing to put the time and effort to get a U.S. credit card, there are much better options than the Disney card. And don't forget, generally speaking, using U.S. credit cards in Canada is typically not as worthwhile as using U.S. credit cards in the U.S. You are better off with a high-earning Canadian credit card for your spend in Canada, and a no-forex fee Canadian credit card for your U.S. spend (unless of course you live a chunk of the year in the U.S., at which point U.S. credit cards become much more appealing in terms of rewards).
As for the best way to earn a lot of points to pay for Disney trips, the best way is to sign-up for credit cards to get the sign-up bonuses. Sign-up bonuses come in all sorts: Aeroplan points, WestJet dollars, cashback, travel points, hotel points, etc., so you will need to determine what you want to pay for with points. For example, the
TD Aeroplan Visa Infinite has a 20k Aeroplan point sign-up bonus and a buddy pass. With that, you could basically pay for one ticket to Orlando, use points for another and use the buddy pass for a third. If you need more than three tickets, you can sign-up for a card, and your spouse can sign up for a card. That way, you could essentially pay for two tickets, and get a total of six people travelling. And that credit card offers a free checked bag for up to nine people traveling on the same reservation as the cardholder. That's just one example, but there are many credit cards that you can sign-up for, each with its own sign-up bonus. And as long as you use the credit cards responsibly (i.e., not keep a balance on them), you should be able to sign up for multiple credit cards a year (and cancel before the second year annual fee comes due), with no impact on your credit score.