At minimum you need to open things up under there. Pull the soaked insulation out and toss it. It has to be replaced with new. Run a fan on the rest of it to speed up the drying process, however long that takes.
Once insulation gets wet, it never dries out. Like a sponge it holds water.
Be sure it's dry before you seal it up.
Very doable and successful if done right.
Please don't ask how I know these things.