So we're staying 4 nights @ the same hotel (Marriot Newport Beach) under 4 separate reservations, switching accts every other night.

What are the chances the certificates post immediately within 24 hrs so that we could just extend our trip by 2 more days?

Also, should I reach out to the hotel in advance to let them know what we're doing? I'd like to be up front and find out if there's any way to just keep our room for the duration of our stay rather than going through the inconvenience since it's surely easier for the hotel and house cleaning. I don't mind doing the check in/out process but would like to just keep all luggage and stuff in one place. Also I'm Gold Elite and my wife has no status so I'm going to see if we can't get upgraded to an ocean view.

Who'd be the most effective/helpful person to reach out to about this; room manager, hotel manager?