I've changed proposal plans 3 or 4 times at this point, but the snow idea came up today at lunch.
Original plan (and still standing unless I can do something with the snow idea) is at MK the day we get there, Snow White's wishing well, cheesy lines from me, etc. etc., and I've got ADR's for Cali Grill that night.
Snow because she loves all things winter and Christmas, and thanks to some bugs in her ear, she thinks i'm waiting for it to snow here to propose. (That was my initial plan before I booked the WDW trip.)
I've seen the video of the Snowground at the Trading Post, about to look up the sing-along.