CANCEL a cruise? Why on earth would someone do that?!
Okay, seriously, a fair question, and the answer is I do not know because I never asked and have not gone down that path. With other charges (not just
DCL, but, you know, the "real" world) charges get credited back to the card on which the payment was charge. For a typical VISA, MC, or Amex, for example. Would Disney put Dollars back on my Disney Card? Perhaps--I just don't know, and it might be somewhere in the fine print (I'm a lawyer but I don't bother to read it, either) of the card agreement. Possibility that I might forfeit, considering it is not truly "cash" but really a bonus of sorts, subject to conditions.
And yes, I bought the trip protection insurance!!
Your wait until the end idea is the most prudent--I just have to admit I got too excited to do nothing so making the interim payments and using Rewards Dollars to do so seemed fun.
Still, between the rewards dollars and the $1,049 in coins from pocket change my family accumulated in a giant coke bottle "bank" and designated as the cruise fund, and the DU rebate, more than half of the cost of the cruise was covered by painless methods.