Sounds like you have it figured out.
In case you haven't tested it out, the host can send the other player their save game files (located in Documents/Larian Studios/Divinity Original Sin/Player Profiles/PROFILE NAME/Savegames ), and then the 2nd player can load it up and do things solo without messing up the host's save. Like if you want to test out crafting or look over your character's current stats when the host isn't around.
