Sherrie, not sure about whether that whipped ganache is freezable- in Rose’s white ganache, which is basically whipped cream stabilized with white chocolate, the chocolate equals 39% of the weight of the cream. In the Milky Way tart, it’s less than that. If it doesn’t have any starch or gelatin, I’d definitely test freeze a tiny amount.
You might be able to get it to freeze if you work in some tapioca/cassava starch in the same proportions and manner as the corn starch stabilized whipped cream from the Cake Bible (tapioca starch is freezable, but corn starch is not). Gelatin should also allow it to freeze.