Overthinking again, Park and Cruise motel, New Orleans edition

[Amy Paperlady]

I have posted the next paragraph Elsewhere offsite, but I figure I may just et more useful answers here... The cruise in question is on the Carnival Glory, leaving October 8 (3 weeks!)

 

So, we'd already booked a room in Slidell, and were planning to park at Fulton. Now, plans have changed (there's a church we want to visit) and we've booked the La Quinta in Gretna, with the parking package. How does the parking generally work? If we drive to the church, could we get back into the parking lot (it would be after check out time)? Should we ask for a later check out time, and get back into the parking lot before then? Should we Uber or whatnot to church, go back to the parking lot, and get our luggage and shuttle to the port? Am I overthinking this? (Quite probably...)