We are adding the ability to have multiple products per idea portal. This will also allow the possibility of multiple idea portals for the same product(s). So you will be able to have a submit-only portal and a private portal that cover the same ideas.
The configuration of idea portals will move from the Product Settings to the Account Settings section. This will allow a single portal to span multiple products. If you configure you portal with multiple products then users will be prompted to choose the product before creating a new idea.