As someone who uses IntelliJ at the moment, this is an interesting thought to me. What would your workflow look like? In-IDE terminal + Vim for code editing and the rest of the IDE for refactoring, running code, etc.?
Or did you mean use Vim bindings in IntelliJ?
Using vi key bindings is the easiest way to use IntelliJ, IMO. That's how I use my PyCharm and it's amazing. You can even tell your IDE to use your .vimrc.