Whoa! It has been awhile for you! The quote you got for PO sounds really good if that included tickets. Not sure how fast Wilderness goes, but April is a very busy month with many surrounding states giving kids a week off for Spring Breaks. I couldn't get a single room in val or mod last year during that time. Had to stay off site

It wasn't pretty!
Yes, if you book a spot now and a code comes out you can apply it or they cancel and rebook you, whatever it takes to get you the best rate. I've done this myself through Disney Travel and AAA did it for me this year too when a
free dining pin came out.
They ask for a $200 deposit and then payment in full 45 days out. I have a Disney Visa and they give 6 months 0% interest on any disney package that includes tickets & room. That means when I make my final payment 45 days from the time I go, I can still have 6 months to pay for my trip with no interest. (Not that I'd do that, I prefer to pay before I vacation or else it's no fun.) Still, if you need a little buffer just to get your cruise in there, you know you've got that 0% option on your Visa.
Hope that helps!