That's a good idea. I've already a few nights complete, so I can make sure I put a couple of my cheaper stays on the Platinum. I should have about 20 stays this year, so I'll make sure I hit the 5 on the plat card to be safe.

I wonder if I can put a deposit on my account at check-in using the gold card, but still pay the balance on the platinum?

I'm not just trying to maximize the total number of points, but am also trying to shift some of our accumulation to my wife's aeroplan account to bring it up to a level at which we can redeem on an upcoming trip for one of the tickets. I seem to rack up points at about 10x the rate of my wife--we don't share the purchases enough!