There are no plans that incorporate park hoppers, you have to make one for each park for whatever part of the day you plan to be there. If you do not go to a park on Monday, what will you do otherwise? If you don't really have other plans, I would get 4 day hoppers and go both days. Crowds will be less on Friday morning than on Monday afternoon/evening, but you will likely be more tired on Friday morning so you might want to sleep in before the end of your trip. It's really personal preference.