I tried using this as topping for a key lime cheesecake. Normally I'd whip it up just before serving but I was bringing it to a party and needed to put it together a couple hours beforehand. I was afraid the cream would deflate and weep during that time, so warily, I tried using a little gelatin to help the whipped cream keep its shape. (1 teaspoon gelatin, 1 tablespoon cold water, bloom, then heat until gelatin dissolves, mix in after cream had been whipped to soft peaks.) It was a total disaster. The minute the warm gelatin hit the cold cream it turned into a big blob and left gelatinous strings throughout the cream. When you can't whip cream on the spot before serving, is there a recommended way to stabilize?

Working with gelatin can be challenging at times because of the temperature of the other items. If the gelatin is too hot, things will deflate; if it's too cold, the gelatin will set before you can incorporate it. My guess is that the gelatin should have been left too cool a bit further and also incorporated a bit sooner in the whipping process as described here. Alternatively, you could make a meringue to top the pie which will hold nicely for quite some time and you won't have to worry about it. Cheers!

Have you tried a small amount of xanthum gum (~1/4-1/2t per cup cream), or perhaps powdered sugar (which contains cornstarch) if you don't mind sweetening the cream?

I don't think xanthan gum would be appropriate for this. With my limited experience with xanthan gum, I believe it is used more for baked goods; besides, chantilly cream is so easy to make, it can be made at the last minute. Powdered sugar can most definitely be used to sweeten chantilly cream; many chefs prefer it because it melts more easily. Cheers!