How close are you to being able to get another ticket? It's only two more weeks, they may still have stock of the discounted tickets afterwards but no guarantees on that. If you are close, do you have a rexall nearby? or another store that has a quick posting of miles? I don't think the shop the block miles will post in time for the discounted tickets (if you participated). I'd do the math and see how many more miles you need to get the two tickets at regular cost (since they are posted you can see how much they would be).
Assume you want them in hand two months before so you can book fastpasses (or one if you are staying offsite) and one or two weeks for delivery, could be faster but I wouldn't want to risk it. How many weeks do you have to get how many miles?
If it were me, and I was close to having one more ticket, I'd probably pay out of pocket for one and hope to use airmiles for the other. I would not want to have to pay full price or have a price increase before I can get them. I don't always earn a lot of airmiles in any week, I know some are good about getting 100 a week or whatever their target is, can you do that?
There are other options though, you could use
undercover tourist which is better than Disney prices, but obviously not free like airmiles or as big a discount as the CND deal.