Amex biz plat in Canada is $399. There is no travel credit for biz plat, only the personal plat.

SPG only need 10 stays, which include award booking. So, I guess another option is to see if there are any cheap cat 1 weekend redemption that you can do on your wife account. Open a AMEX SPG for $120 fee and get the sign-up bonus to pay for some of these redemption .

Hope this help you brainstorm other ideas.