Okay, successfully soldered the connection to the flexwatt for the incubator! Man, it was HARD to get the solder to stick to the flexwatt. I'm not sure if it was just that I hadn't melted enough plastic out of the way? Or if my cheap-tastic $5 soldering iron wasn't really hot enough for that join?

...but it seems to work, and the flexwatt is heating up. Now let's see how long it takes to get 12 bottles of arrowhead water to 89F...