It’s possible. You can plug in both textures as well as materials into the image widget. It’s not just the image widget by the way; widgets like the button can have one too; you just have to search the settings a bit since it is not really all that obvious.
Furthermore, if you make the image variable, in the event graph you can call Get Dynamic Material, which will return the dynamic version of the material you plugged in, so you can directly control the parameters.