The large Jambo parking lot begins across the street from the Jambo front entrance area. How close you are to Jambo simply depends on where you find a parking place in that lot, near to far away. Likely in the morning, it will be far.
Nevertheless, the travel distance and time will undoubtedly be less and much quicker than if you take the shuttle (and then take it back to Kidani). Your room at Kidani can be very far from the shuttle -- the building is about 2/3 miles long (one of the longest single hotel buildings on earth) and thus you could have up to a 1/3 mile walk to cover just to get from your room to the shuttle at the the front entrance area. But regardless of where your room is, you can park fairly close to it. There are three elevators along each of the two wings and your room will be somewhere near one of those elevators, and the parking lot is essentially the first floor of Kidani and runs almost one end to the other, with the result that you can usually park somewhere fairly near an elevator that gets you fairly quickly to your room.
As to your usage of the car, be aware of the current issues you may face. When you park in a theme park parking lot, your car can be very far from the front gate. Pre-Pandemic, there were always shuttles that took you from the parking areas to the front gate areas (or Ticket and Transportation Center at MK). For a long time after reopening post-pandemic, those were gone, resulting in your having to walk from your parking spot to the front gate area. They have returned to MK and AK. However, as far as I am aware, they are still missing from Studios and Epcot with no date given yet for their return. Also, if going to MK in the morning before the park opens to about two hours after it is open, be aware there have been huge traffic jams just to get into the parking lot, e.g., the waits, once you are getting near the entry area, can be greater than 1/2 hour. In other words, you need to give serious thought as to whether you really want to use a car rather than a bus to get to a park other than AK.